CN219017120U - Junior middle school physical problem solving board applying ohm law and electric power - Google Patents

Abstract

The utility model discloses a junior middle school physical problem solving board applying ohm law and electric power, solving the problem of electric power by relying on the problem of nine Gong Gejie ohm law and by relying on twelve grids, wherein each grid is formed by nine small grids of 3*3, each small grid is filled with a value of a physical quantity, and each physical quantity in each small grid can be randomly adjusted in position; twelve boxes are composed of 4*3 or 3 x 4 twelve small boxes, each small box is filled with a value of a physical quantity, the positions of the physical quantities in the small boxes can be adjusted at will, and the physical quantities in the same column in the small boxes are solved. The beneficial effects of the utility model are as follows: all calculation solving problems about ohm law and electric power of junior middle school can be completely solved, students are helped to greatly improve the speed of solving complex electric ohm law and electric power problem types, efficient learning is achieved, teachers are helped to rapidly explain the problem, the problem type speed of explaining the ohm law and the electric power is greatly improved, and efficient class is achieved.

Description

Junior middle school physical problem solving board applying ohm law and electric power

Technical Field

The utility model is used in the field of education and teaching, in particular to a physical problem solving board for junior middle school applying ohm's law and electric power.

Background

"calculate" means: accounting the number, and calculating an unknown quantity according to the known quantity; and (5) calculating. A large number of calculation-related questions can be encountered in the physical teaching process, particularly more calculation is performed in the electric learning process, and common questions for calculating the electric power and the electric power according to the electric law are space filling questions, selection questions, calculation questions and experiment questions. The traditional problem solving method is to solve a correct answer through calculation after the relation between the known quantity and the unknown quantity is established, and a great number of investigation and teaching practices prove that most students cannot intuitively establish the relation between the known quantity and the unknown quantity, and the main reasons are that the number of the known physical quantities given by the problem stems is small, the number of the hidden physical quantities is too large, and students cannot directly establish the relation between the known physical quantities and the required physical quantities, so that problems which cannot be solved accurately or problems which cannot be solved manually can not be considered appear; when a teacher explains ohm law and electric power and relates to the problem type of calculation, the teacher generally speaks the relation between known physical quantity and unknown and applies formulas and the like, so that the final result is analyzed, and students with poor work cannot understand the result at all. The utility model is based on the defects, and can greatly improve the problem solving speed of students and the problem teaching speed of teachers.

Disclosure of Invention

The utility model aims to provide a junior middle school physical problem solving board applying ohm law and electric power, which solves the calculation problem of physical and electric ohm law and electric power, fills the physical problem solving board into a specific small square according to the known physical quantity of a problem stem, and can fill all unknown physical quantities in the small square by utilizing the series-parallel rule of a circuit, ohm law and electric power calculation formula when the filling quantity meets a certain quantity, thereby greatly improving the problem solving speed of students and the problem teaching speed of teachers.

The technical scheme adopted by the utility model is as follows: a physical problem solving plate for junior middle school applying ohm's law and electric power is rectangular or square, and comprises a bottom plate, a frame and a groove, wherein the bottom plate is externally provided with a frame, and the groove is arranged in the frame; the method is characterized in that: when the problem solving plate is square, setting a nine-square lattice, setting the nine-square lattice as nine small squares, and placing the nine small squares in the groove; when the solving plate is rectangular, the solving plate is set to be twelve grids, the twelve grids are set to be twelve small grids, and the twelve small grids are placed in the grooves.

Further, one surface of the groove bottom plate is provided with a line drawing, and the line drawing is formed into nine small squares or twelve small squares, so that the small squares are conveniently placed in the grooves.

Furthermore, a certain area is arranged on the left side and the right side of the frame on the same surface as the groove, and a plurality of formulas are drawn on the area of the frame.

Further, when the solving plate is square, nine physical quantities are respectively carved on the nine small squares, and each physical quantity comprises three voltage values, three current values and three resistance values, wherein the voltage values are U ₁ 、U ₂ And U _{Total (S)} The current value is I ₁ 、I ₂ And I _{Total (S)} The resistance value is R ₁ 、R ₂ And R is _{Total (S)} 。

Further, when the solving plate is rectangular, twelve physical quantities are respectively marked on twelve small squares, and each physical quantity comprises three voltage values, three current values, three resistance values and three power values, wherein the voltage values are U ₁ 、U ₂ And U _{Total (S)} The current value is I ₁ 、I ₂ And I _{Total (S)} The resistance value is R ₁ 、R ₂ And R is _{Total (S)} The power value is P ₁ 、P ₂ And P _{Total (S)} 。

Further, some formulas are drawn on the frame area, and are respectively:

series circuit

；

Parallel circuit

；

The formula and variants of ohm's law are:

；

formula and deformation type of electric power

。

Furthermore, according to personal preference and habit, the design change of the nine or twelve grids changes the positions of the physical quantities in the small grids, the use modes are the same, and the specific arrangement sequence can be as follows:

when the solving plate is square, the arrangement sequence of the nine boxes is as follows: the first row has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third current values of the second behavior are respectively I ₁ 、I ₂ And I _{Total (S)} The third behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} ；

The second arrangement sequence of the nine boxes is either: the first row is three current values, respectively I ₁ 、I ₂ And I _{Total (S)} The second behavior has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} ；

The third arrangement sequence of the nine boxes is as follows: the first row has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The third current values of the second behavior are respectively I ₁ 、I ₂ And I _{Total (S)} The third behavior has three voltage values, U ₁ 、U ₂ And U _{Total (S)} ；

The fourth arrangement sequence of the nine boxes is as follows: the first row is three current values, respectively I ₁ 、I ₂ And I _{Total (S)} The second behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The third behavior has three voltage values, U ₁ 、U ₂ And U _{Total (S)} ；

The fifth arrangement sequence of the nine squares is as follows: the first row has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The second behavior has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third behavior has three current values, I ₁ 、I ₂ And I _{Total (S)} ；

The sixth arrangement sequence of the nine boxes is as follows: the first row has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The second behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The third behavior has three current values, I ₁ 、I ₂ And I _{Total (S)} ；

The seventh arrangement sequence of the nine boxes is as follows: first behavior current value I ₁ Voltage value U ₁ Resistance value R ₁ Second behavior current value I ₂ Voltage value U ₂ Resistance value R ₂ Third behavior current value I _{Total (S)} Voltage value U _{Total (S)} Resistance value R _{Total (S)} ；

The eighth arrangement sequence of the nine boxes is as follows: first behavior voltage value U ₁ Current value I ₁ Resistance value R ₁ Second behavior voltage value U ₂ Current value I ₂ Resistance value R ₂ Third behavior voltage value U _{Total (S)} Current value I _{Total (S)} Resistance value R _{Total (S)} ；

Wherein the arrangement sequence of the nine boxes can be adjusted and changed.

When the solving plate is rectangular, the arrangement sequence of the twelve boxes is as follows: the first is three power values, respectively P ₁ 、P ₂ And P _{Total (S)} Second behavior three electricThe pressure values are U respectively ₁ 、U ₂ And U _{Total (S)} The third behavior has three current values, I ₁ 、I ₂ And I _{Total (S)} The fourth behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} ；

The second arrangement sequence of the twelve boxes is as follows: the first row has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third current values of the second behavior are respectively I ₁ 、I ₂ And I _{Total (S)} The third behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The fourth behavior is three power values, P ₁ 、P ₂ And P _{Total (S)} ；

The third arrangement sequence of the twelve grids is as follows: first electric power value P ₁ Voltage value U _1、 Current value I ₁ Resistance value R ₁ Second behavioural electric power value P ₂ Voltage value U ₂ Current value I ₂ Resistance value R ₂ Third behavior electric power value P _{Total (S)} Voltage value U _{Total (S)} Current value I _{Total (S)} Resistance value R _{Total (S)} ；

The fourth arrangement sequence of the twelve grids is as follows: first behavior voltage value U ₁ Current value I ₁ Resistance value R ₁ Electric power value P ₁ Second behavior voltage value U ₂ Current value I ₂ Resistance value R ₂ Electric power value P ₂ Third behavior voltage value U _{Total (S)} Current value I _{Total (S)} Resistance value R _{Total (S)} Electric power value P _{Total (S)} ；

Wherein the arrangement sequence of the twelve grids can be changed in an adjustable way.

Furthermore, according to the habit of teaching or personal use, the manufacturing form of the question solving plate is used as a sticky note, a draft book, a seal and a teacher. Or printed into books and data.

The problem of electric power is solved by relying on nine Gong Gejie ohm law and by relying on twelve grids, wherein the nine grids are formed by nine small grids of 3*3, each small grid is filled with a value of a physical quantity, and the positions of the physical quantities in the small grids can be adjusted at will; twelve palace lattice is composed of 4*3 or 3 x 4 twelve small square grids, each small square grid is filled with a value of a physical quantity, and each physical quantity in each small square grid can be adjusted at will;

Specifically, the problem solving method of the junior middle school physical problem solving plate by using ohm law and electric power is characterized by comprising the following steps:

step one: analyzing the connection form of the circuit, and determining the measuring objects of the ammeter and the voltmeter; the connection form of the circuit is as follows: the electric appliances are connected in an independent mode, a serial circuit, a parallel circuit, a serial-parallel circuit, a parallel-parallel circuit, the serial connection of three electric appliances and the parallel connection of three electric appliances;

step two: drawing a corresponding nine-square or twelve-square according to the connection form of the circuit, and filling the corresponding known physical quantity into the corresponding small square;

step three: "identity", "simultaneity" and "unification" of the control circuits;

the identity refers to one-to-one correspondence of a current value, a voltage value, a resistance value and electric power of a section of circuit; for example resistance R ₁ The voltage, current, resistance, electric power of (a) are corresponding, the resistance R is not confused ₂ Is worn by Zhang guan Li;

the term "concurrency" refers to that when a circuit is turned on, a current value, a voltage value, a resistance value and electric power can be correspondingly used, and when the circuit is changed, the current value, the voltage value, the resistance value and the electric power cannot be directly utilized, and whether the current value, the voltage value, the resistance value and the electric power can be continuously used at the last moment must be judged; for example, when the switch S is closed at one moment, the two electric appliances are connected in series, the switch S is opened at the next moment, the two electric appliances are connected in parallel, the physical quantity obtained at the last moment cannot be directly used in the circuit at the next moment, the quantity which can be utilized is judged according to the actual condition of the circuit, the voltage of a general power supply is unchanged and can be utilized, the resistance value of a resistor is unchanged and can be utilized, and the current in the circuit and the voltage of each electric appliance are generally changed and cannot be used at will;

The 'unification' means that each physical quantity unit needs to be uniformly in international units, voltage units, current units, resistance units, ohm units and watt units, and the physical quantity which is not the international units needs to be converted into the international units and is uniformly used in a nine-grid and a twelve-grid;

step four: observing the number and the existence positions of the known physical quantities of the nine-square or twelve Gong Gezhong-square, wherein at least 3 known physical quantities are required to be satisfied in the square, and meanwhile, the 3 physical quantities cannot be in the same horizontal row or the same vertical row, or only 2 physical quantities are required to be in the square, so that all the physical quantity information cannot be solved; or only 3 physical quantities in the small square, and the 3 physical quantities exist in the same horizontal row or the same vertical row, so that all physical quantity information cannot be solved; three known quantities are not valid in the same row or column, and the stem is the wrong question; but two known amounts in the same row or column are feasible;

step five: solving the physical quantity of the same row in the small square by utilizing the laws of current, voltage, resistance and electric power of the circuits connected in series and in parallel;

the specific rules are as follows:

Series circuit

；/>

Parallel circuit

；

Step six: solving the physical quantity of the same vertical column in the small square by using the formula and the deformation of the ohm law and the formula and the deformation of the electric power;

the formula and the deformation of ohm law are as follows:

；

formula and deformation of electric power

。

In the second step, a plurality of nine-grid or twelve-grid cells may be used in combination with the "simultaneity" principle of the third step.

In the fourth step, the number and the existing positions of the known physical quantities of the nine-square or twelve Gong Gezhong-square are observed, if the known physical quantity contains electric power or the solving physical quantity is electric power, the twelve-square is adopted, and the rest of the known physical quantities do not contain electric power or the solving physical quantity is not electric power, and the nine-square is adopted.

The utility model has the following functional advantages: the first method is simple, easy to be put on hand and easy to be understood; secondly, the numerical value of each physical quantity and the change condition of the reflected numerical value can be rapidly calculated; thirdly, the value of an ammeter in the circuit, the value of a voltmeter and the change condition of the size of the ammeter can be reflected; fourthly, the step sequence of solving the problems can be displayed, so that the problem solving process can be conveniently written; fifthly, the student can be helped to understand ohm's law and electric power; the students can be helped to greatly improve the speed of solving the complex electric ohm law and electric power problem type, and the students can learn with high efficiency; seventh, the physical learning confidence of students can be enhanced; eighth, can help the teacher to explain the question fast, raise and explain the question speed about ohm law and electric power greatly, the high-efficient classroom; the ninth energy covers almost all the physical electric plates of the junior middle school and relates to all the calculation questions, the coverage is wide, and the adaptability is strong; tenth, students can be helped to lay an electrical foundation, and a tamping foundation is laid for the Xi Oum law of high school.

The beneficial effects of the utility model are as follows: (1) All solution problems for ohm's law and electric power in junior middle school can be solved, including but not limited to: the method comprises the steps of ohm law calculation, electric power calculation, electric physical quantity calculation according to images, electric physical quantity calculation according to ratios, electric physical quantity calculation by a dynamic circuit, electric physical quantity judgment by a dynamic circuit, electric physical quantity change condition judgment by a dynamic circuit, electric physical quantity change range judgment by a special method, resistance calculation by a special method, rated power calculation by a special method, data error judgment by a table, slide rheostat specification selection judgment, multi-gear problem judgment, electric power and electric energy calculation, application of a sensitive resistor, electric power synthesis and electric heat synthesis; (2) The method solves the calculation problems of the physical and electrical ohm laws and the electric power, firstly writes all physical quantities in a circuit into small squares, fills the physical quantities into specific small squares according to the known physical quantities of the problem stems (or can solve the problem smoothly only by using 2 small squares according to the problem), wherein the small squares can be designed into nine or twelve squares according to the problem requirement, and when the filling quantity meets 3 (the 3 filled physical quantities cannot be physical quantities of the same row or column), the series and parallel rules of the circuit, ohm laws and electric power calculation formulas can be utilized to fill all unknown physical quantities in the small squares.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Fig. 2 is a schematic diagram of a nine-grid arrangement according to the present utility model.

Fig. 3 is a diagram showing a nine-grid arrangement of the present utility model.

Fig. 4 is a three schematic diagram of a nine-grid arrangement of the present utility model.

Fig. 5 is a schematic diagram of a twelve-grid arrangement according to the present utility model.

Fig. 6 is a schematic diagram of a twelve-grid arrangement according to the present utility model.

Fig. 7 is a schematic diagram of a twelve-grid arrangement according to the present utility model.

Fig. 8 is a schematic diagram of an embodiment of the present utility model.

Fig. 9 is a schematic diagram of a second embodiment of the present utility model.

Fig. 10 is a schematic diagram of an embodiment of the present utility model.

Fig. 11 is a schematic diagram of an embodiment of the present utility model.

Fig. 12 is a schematic diagram of a fifth embodiment of the present utility model.

Fig. 13 is a diagram showing a sixth embodiment of the present utility model.

Fig. 14 is a seventh schematic diagram of an embodiment of the present utility model.

Fig. 15 is an eighth schematic view of an embodiment of the present utility model.

Fig. 16 is a diagram of a ninth embodiment of the present utility model.

Fig. 17 is a schematic diagram of an embodiment of the present utility model.

Fig. 18 is a diagram of an eleventh embodiment of the present utility model.

Fig. 19 is a schematic diagram of an embodiment of the present utility model.

Description of the embodiments

As shown in fig. 1, a solution board for junior middle school physics applying ohm law and electric power is rectangular or square, and comprises a bottom plate 1, a frame 2 and a groove 3, wherein the bottom plate 1 is externally provided with a frame 2, and the groove 3 is arranged in the frame 2; the method is characterized in that: when the problem solving plate is square, the problem solving plate is set to be a nine-square grid, the nine-square grid is set to be nine small squares 4, and the nine small squares 4 are placed in the groove 3; when the solving plate is rectangular, the solving plate is set to be twelve grids, the twelve grids are set to be twelve small grids 4, and the twelve small grids are placed in the grooves 3. Fig. 1 is merely an exemplary diagram, and the solving plate may be colored, may be of different sizes, may place formulas on the back of the base plate, etc.

The utility model will show the figure of the nine-square or twelve-square according to the preference of the user; FIG. 2 shows a nine Gong Gedi-behavior of three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third current values of the second behavior are respectively I ₁ 、I ₂ And I _{Total (S)} The third behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The method comprises the steps of carrying out a first treatment on the surface of the Fig. 3 shows a second arrangement of the nine squares or: the first row is three current values, respectively I ₁ 、I ₂ And I _{Total (S)} The second behavior has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The method comprises the steps of carrying out a first treatment on the surface of the Fig. 4 shows a third arrangement of the nine squares or: first behavior current value I ₁ Voltage value U ₁ Resistance value R ₁ Second behavior current value I ₂ Voltage value U ₂ Resistance value R ₂ Third behavior current value I _{Total (S)} Voltage value U _{Total (S)} Resistance value R _{Total (S)} The method comprises the steps of carrying out a first treatment on the surface of the Fig. 5 shows twelve Gong Gedi for three power values, P respectively ₁ 、P ₂ And P _{Total (S)} The second behavior has three voltage values, U ₁ 、U ₂ And U _{Total (S)} The third behavior has three current values, I ₁ 、I ₂ And I _{Total (S)} The fourth behavior has three resistance values, R ₁ 、R ₂ And R is _{Total (S)} The method comprises the steps of carrying out a first treatment on the surface of the Fig. 6 is a schematic diagram of a twelve-grid arrangement according to the present utility model. Fig. 7 is a schematic diagram of a twelve-grid arrangement according to the present utility model.

The utility model works and implements in this way, according to the content of the utility model, can be suitable for solving the problem types such as filling problem, choice problem, experiment problem, calculation problem, etc., specifically, 16 types are classified according to the knowledge point processing mode.

Embodiment one: for ohm's law calculation, it is common to fill in the blank, select and calculate questions.

As in the circuit shown in FIG. 8, R is known experimentally ₁ 20 omega, in case of closing S, opening S ₁ The reading of the time ammeter is 1.5A, S is closed ₁ The current meter reading is 2.1A, the voltage of the battery is unchanged throughout the experiment, ask (1) how much is the supply voltage (2) through R ₂ What is the current of (3) the measured resistance R ₂ Is the resistance of?

The problem solving method according to the utility model comprises the following specific steps:

judging the serial and parallel connection modes of the circuits, and judging the measuring objects of the ammeter and the voltmeter at the same time; the present embodiment is R ₁ And R is ₂ The parallel circuit of the circuit breaker, the ammeter measures the trunk current;

step two, as shown in figure 8, drawing a small square corresponding to the nine square, the physical quantity related to the example problem is resistance R ₁ Voltage U of (2) ₁ Current I ₁ Resistance R ₁ The method comprises the steps of carrying out a first treatment on the surface of the Resistor R ₂ Voltage U of (2) ₂ Current I ₂ Resistance R ₂ The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Main current I _{Total (S)} Total resistance R _{Total (S)} ；

Step three, the stem is put intoThe known physical quantity is filled into the small square, and the known physical quantity is the resistor R in the embodiment ₁ Resistance value 20 omega, current I ₁ 1.5A, main current I _{Total (S)} 2.1A;

step four, checking whether each physical quantity accords with 'identity', 'simultaneity', 'unification';

and fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection form of the circuit by utilizing the rules of current, voltage and resistance. The present embodiment is R ₁ And R is ₂ Can be filled with the voltage U of the power supply _{Total (S)} 30V, voltage U ₂ 30V, current I ₂ 0.6A;

step six, utilizing ohm law formula and deformation formula

And solving the corresponding physics. Voltage U in this example ₁ Can solve 30V and resistance R ₂ 50 omega can be solved.

And step five and step six belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the above process, several problems of the embodiment are completed, and meanwhile, the sequential process of solving each physical quantity is noted in the small square, so that students are effectively helped to quickly and accurately complete problem solving.

Embodiment two: calculation of electric power.

As in the circuit of fig. 9, the supply voltage is 12V and remains unchanged. With lamps L interposed between ab ₁ "4V 2W", closing the switch, adjusting the slide P to make the lamp L ₁ Normally light, the current in the circuit isA, the resistance of the access circuit of the slide rheostat isOmega, disconnecting switch take-down lamp L ₁ The position of the sliding sheet P is kept unchanged, and a lamp L is connected between ab ₂ "4V 4W", lamp L ₂ Is the resistance of (2)_ _Omega, closing switch S, lamp L ₂ Actual power of (3)4W (optional "greater than", "equal to" or "less than").

The problem solving method according to the utility model comprises the following specific steps:

First, judge the serial and parallel connection of the circuit according to the questionsAnd simultaneously judging the measuring objects of the ammeter and the voltmeter. The embodiment is a resistor R and a lamp L ₁ Is a series circuit of (1) and is measured by a voltmeter ₁ A voltage.

Second, as shown in fig. 9, a twelve square lattice is drawn, corresponding to the twelve square lattice. The physical quantity related to the embodiment is a lamp L ₁ Voltage U of (2) ₁ Current I ₁ Resistance R ₁ Electric power P ₁ The method comprises the steps of carrying out a first treatment on the surface of the Voltage U, current I, resistance R, electric power P of resistance R; voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} Total electric power P of circuit _{Total (S)} 。

Third, the known physical quantity in the stem is filled into the small square cells ₁ =4V、P ₁ =2W、U _{Total (S)} =12v。

Fourth, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection mode of the circuit by utilizing the rules of current, voltage and resistance. The embodiment is a resistor R and a lamp L ₁ Can be filled with a voltage u=8v and a current i=0.5a.

Sixth, using ohm's law equation and deformation equation

And solving the corresponding physics. Current I in this example ₁ 0.5A can be solved and the resistance R can be solved for 16Ω.

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the above process, the 1 st and 2 nd empty solutions I of the problems are completed ₁ The method has the advantages that the method is=0. A, R =16Ω, and meanwhile, the sequential process of solving each physical quantity is noted in the small square, so that students are effectively helped to finish the process quickly and accurately. The problem is a blank filling problem, the blank filling problem can remove the sequential process of labeling and solving each physical quantity, and the problem solving speed can be improved.

The present utility model is applied again to this problem, first, the present embodiment is a resistor R andlamp L ₂ Is a series circuit of (1) and is measured by a voltmeter ₂ A voltage.

Second, a small square corresponding to the twelve boxes is drawn. The physical quantity related to the embodiment is a lamp L ₂ Voltage U of (2) ₂ Current I ₂ Resistance R ₂ Electric power P ₂ The method comprises the steps of carrying out a first treatment on the surface of the Voltage U, current I, resistance R, electric power P of resistance R; voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} Total electric power P of circuit _{Total (S)} 。

Thirdly, the known physical quantity in the stem is filled in the small square lattice. According to lamp L ₂ We can solve the lamp L first ₂ The resistance of (2) is 4Ω. The known physical quantity is R ₂ =4Ω、R=16Ω、U _{Total (S)} =12V。

Fourth, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection mode of the circuit by utilizing the rules of current, voltage and resistance. The embodiment is a resistor R and a lamp L ₂ Can be filled with R _{Total (S)} =20Ω，I ₂ =0.6A。

Sixth, using ohm's law equation and deformation equation

The method comprises the steps of carrying out a first treatment on the surface of the Electric power calculation formula and deformation formula>

And solving the corresponding physics. In this embodiment I _{Total (S)} =0.6A，U ₂ =2.4V，P ₂ =1.44W。

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the process, the solution R of the 3 rd and 4 th spaces of the problem is completed ₂ =4Ω、P ₂ The problem is a blank problem, which can remove the sequential process of labeling and solving each physical quantity, and can further improve the problem solving speed.

In the third embodiment, a certain electrical physical quantity is calculated according to the image.

As shown in FIG. 10, the power supply voltage in the A circuit is unchanged, the maximum resistance value of the sliding rheostat is 80 omega, the range of the ammeter is 0-0.6A, and the range of the ammeter is 0-15V. When all switches are closed, the relation between the electric power and the connection resistance of the slide rheostat in the moving process of the slide sheet P between the points a and b is shown as a graph B, and the ratio of the voltage representation numbers of the slide sheet P at the points a and b is. S, S1 is closed and opened, and the difference between the maximum power and the minimum power of the sliding rheostat is as follows in order to ensure the circuit safety W。

The problem solving method according to the utility model comprises the following specific steps:

the first basis is to judge the serial and parallel connection modes of the circuits and judge the measuring objects of the ammeter and the voltmeter. The embodiment is a constant resistor R ₁ And a series circuit of the sliding rheostat resistor R, the voltmeter measures the voltage of the sliding rheostat resistor R, and the ammeter is short-circuited.

Second, as shown in fig. 10, a grid corresponding to the twelve grids is drawn. The physical quantity related to the embodiment is written into the small square, and the sliding sheets respectively have different electric power and resistance at the point a and the point b, so that the problem needs to be solved by using 2 small square combinations.

Thirdly, filling the known physical quantity in the stem into the small square lattice. The present embodiment assumes a constant resistance R, where r=50Ω, p=4.5w when the physical quantity is known to be b ₁ Known as a known quantity, the physical quantity of the embodiment is R=2Ω, P=4.5W when the physical quantity is a, and the fixed resistance R is assumed ₁ Is a known quantity.

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

And fifthly, filling corresponding physical quantities in the small square lattice according to the series connection form of the circuit by utilizing the rules of current, voltage and resistance. The embodiment is a constant resistor R ₁ And a resistor R of the slide rheostat, wherein the small square at the position b can be filled with I ₁ =0.3A， U _{Total (S)} =15+0.3R ₁ The small square at the position a can be filled with I ₁ =1.5A， U _{Total (S)} =3+1.5R ₁ 。

Sixth utilizing ohmLaw formula and deformation formula

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. In this embodiment, i=0.3a, u=15v, u at b ₁ =0.3R ₁ I=1.5a, u=3v, u at a ₁ =1.5R ₁ 。/>

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the process, the voltage 3V at a and the voltage 15V at b are solved. Therefore, the ratio is 3 V:15V=1:5, the problem is a blank filling problem, the sequential process of labeling and solving each physical quantity can be removed, the problem solving speed can be improved, and R can be solved on the basis of the problem ₁ =10Ω，U _{Total (S)} =18V。

The utility model is applied to the embodiment again, and the serial and parallel connection modes of the circuit are judged according to the first question, and the measuring objects of the ammeter and the voltmeter are judged at the same time. The embodiment is a constant resistor R ₁ And the serial circuit of the slide rheostat resistor R, the voltmeter measures the voltage of the slide rheostat resistor R, and the ammeter measures the power supply current.

Second, as shown in fig. 10, a twelve square lattice is drawn. The physical quantity according to the present embodiment is written in the small square, and since the slide moves to make R have different electric power, the problem needs to be solved by using the combination of 3 small square.

Thirdly, filling the known physical quantity in the stem into the small square lattice. The known physical quantity of the embodiment is that when the sliding rheostat resistor R and the fixed resistor R ₁ When equal, the sliding rheostat power P is maximum, r=10Ω, R ₁ =10Ω，U _{Total (S)} =18V。

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

Fifth, ohm law formula and deformation formula are utilized

And solving the corresponding physics. Solving R _{Total (S)} =20Ω，I _{Total (S)} The combination of the stem with the current meter range of 0-0.6A is required for =0.9a, so r=10Ω is erroneous.

Sixth, the known physical quantity in the stem is filled in the small square. The physical quantity is known in this embodiment to be the sliding resistor power pmax when the current representation number is maximum. I _{Total (S)} =0.6A、R ₁ =10Ω，U _{Total (S)} =18V。

Seventh, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

And eighth, filling the corresponding physical quantity in the small square lattice according to the series connection form of the circuit by utilizing the rules of current, voltage and resistance. Can be filled with I ₁ =0.6A，I=0.6A，R=20Ω。

Ninth utilizing ohm's law formula and deformation formula

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Solving R _{Total (S)} =30Ω, u=12v, p=7.2w, at which time the sliding varistor power is maximum. (the eighth step and the ninth step belong to sister steps, and are sequentially adjusted and recycled according to requirements).

Tenth, the known physical quantity in the stem is filled in the small square lattice. The physical quantity is known in this embodiment to be the minimum slide varistor power P when the number of voltage representations is maximum. u=15V, R ₁ =10Ω，U _{Total (S)} =18V。

In the eleventh check, whether or not the physical quantities match "identity", "simultaneity" or "uniformity".

And according to the serial connection form of the circuit, filling the corresponding physical quantity in the small square lattice by utilizing the rules of current, voltage and resistance. Can fill U ₁ =3V，I=0.3A。

Thirteenth equation and deformation equation using ohm's law

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Solving for I ₁ =0.3a, p=4.5W, at which time the sliding varistor power is minimal. (the twelfth and thirteenth steps belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Through the above process, the maximum power p=7.2w and the minimum power p=4.5w of the sliding rheostat are solved, so that the power difference is 2.7W, the problem is that the blank problem is filled, the sequential process of labeling and solving each physical quantity can be removed, and the problem solving speed can be improved.

In the fourth embodiment, a certain electrical physical quantity is calculated according to the ratio.

In the circuit shown in FIG. 11, when the switch S is turned off, the first and second parts are connected with the ammeter, and the ratio of the readings is I _{Nail armor} :I _{Second step} When the switch S is closed, the voltage meter is connected to both the first and second positions, and the following determination is correct ().

A. When the switch S is opened, the resistor R ₁ And R is R ₂ Serial connection; B. when the switch S is closed, the resistor R ₁ And R is R ₂ Parallel connection;

C. resistor R ₁ And R is R ₂ The ratio of the resistance values of (2) to (3); D. when the switch S is closed, the ratio of the numbers of the two voltage meters A and B is 5:2.

The problem solving method according to the utility model comprises the following specific steps:

first, the serial and parallel connection modes of the circuit are judged according to the questions, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In this embodiment, the switch S is turned off by a resistor R ₁ And resistance R ₂ The current meter A measures the R2 current and the current meter B measures the trunk current.

Second, as shown in fig. 11, a square is drawn corresponding to the square. The physical quantity related to the embodiment is the resistance R ₁ Voltage U of (2) ₁ Current I ₁ Resistance R ₁ The method comprises the steps of carrying out a first treatment on the surface of the Resistor R ₂ Voltage U of (2) ₂ Current I ₂ Electric powerR resistance ₂ The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} 。

Third, the known physical quantity in the stem is filled into the small square lattice ₂ =3、I _{Total (S)} =5。

Fourth, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection mode of the circuit by utilizing the rules of current, voltage and resistance. The present embodiment is a resistor R ₁ And resistance R ₂ Can be filled with a current I ₁ =2。

Sixth, using ohm's law equation and deformation equation

And solving the corresponding physics. The embodiment belongs to the ratio problem, the specific voltage value is not known, but the characteristic that the parallel circuit branch voltage is equal to the power supply voltage can be utilized to solve the resistance R by assuming the voltage value as U ₁ =3, can solve for the resistance R ₂ =2。

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the process, the judgment of the A and C options of the subject is completed, and the correct ratio of the C options is 3:2. The topics are selected, the sequential process of labeling and solving each physical quantity can be removed from the selected topics, and the problem solving speed can be improved.

The utility model is applied to the problem again, firstly, the serial and parallel connection forms of the circuits are judged according to the problem, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In this embodiment, the switch S is a resistor R when it is closed ₁ And resistance R ₂ The voltage meter A measures the power supply voltage and the voltage meter B measures R ₂ A voltage.

Second, small squares corresponding to the nine squares are drawn. The physical quantity related to the embodiment is the resistance R ₁ Voltage U of (2) ₁ Current I ₁ Electric powerR resistance ₁ The method comprises the steps of carrying out a first treatment on the surface of the Resistor R ₂ Voltage U of (2) ₂ Current I ₂ Resistance R ₂ The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} 。

Third, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Thirdly, the known physical quantity in the stem is filled in the small square lattice. Due to resistance R ₁ And resistance R ₂ All are constant resistors, so the resistance is unchanged, and the known physical quantity of the embodiment is R ₁ =3，R ₂ =2。

Fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection mode of the circuit by utilizing the rules of current, voltage and resistance. The present embodiment is a resistor R ₁ And resistance R ₂ Can be filled with R _{Total (S)} =5。

Sixth, using ohm's law equation and deformation equation

The method comprises the steps of carrying out a first treatment on the surface of the And solving the corresponding physics. The embodiment belongs to the ratio problem, and the specific current value is not known, but the characteristic that the currents of the series circuits are equal everywhere can be utilized to assume that the current value is I, and the voltage U can be solved ₂ =2, can solve for the voltage U _{Total (S)} =5。

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the process, the judgment of B and D options of the subject is completed, and the correct ratio of the D options is 5:2. The topics are selected, the sequential process of labeling and solving each physical quantity can be removed from the selected topics, and the problem solving speed can be improved.

In the fifth embodiment, the dynamic circuit obtains a certain electrical physical quantity.

In the circuit shown in fig. 12, the power supply voltage is 6V constant, and the maximum resistance of the sliding resistor R is 20Ω. Closing the switch, wherein the P-R image of the slide rheostat is shown as a picture B, and R is ₁ =Omega. When the slide P slides to the rightmost end, R ₂ The voltage of two turbulence isV。

The problem solving method according to the utility model comprises the following specific steps:

judging the serial and parallel connection modes of the circuits, and judging the measuring objects of the ammeter and the voltmeter at the same time; the present embodiment is R ₁ And R is ₂ The current meter measures the power supply current;

step two, as shown in fig. 12, draw a small square corresponding to the twelve square, the physical quantity related to this embodiment is the resistance R ₁ Voltage U of (2) ₁ Current I ₁ Resistance R ₁ Electric power P ₁ The method comprises the steps of carrying out a first treatment on the surface of the Resistor R ₂ Voltage U of (2) ₂ Current I ₂ Resistance R ₂ Electric power P ₂ The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Main current I _{Total (S)} Total resistance R _{Total (S)} Total electric power P _{Total (S)} ；

Step three, filling the known physical quantity in the stem into the small square lattice, wherein the known physical quantity is the resistor R ₂ Maximum resistance value of the rightmost end is 20Ω, and power supply voltage U _{Total (S)} R is known by 6V and looking up image ₂ Rightmost electric power P ₂ 0.8W;

step four, checking whether each physical quantity accords with 'identity', 'simultaneity', 'unification';

And fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection form of the circuit by utilizing the rules of current, voltage and resistance. The present embodiment is R ₁ And R is ₂ Can be filled with a voltage U ₁ 2V, current I ₂ 0.2A;

step six, utilizing ohm law formula and deformation formula

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Voltage U in this example ₂ Can solve 4V and resistance R ₁ 10 omega can be solved.

And step five and step six belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the above process, several problems of the embodiment are completed, and meanwhile, the sequential process of solving each physical quantity is noted in the small square, so that students are effectively helped to quickly and accurately complete problem solving.

In the sixth embodiment, the dynamic circuit determines the change condition of a certain electrical physical quantity.

As shown in FIG. 13, a photoresistor R and a constant resistor R are combined ₀ The ammeter, voltmeter, switch and power supply are connected into a circuit as shown. The resistance of the photoresistor decreases with increasing illumination intensity. Closing the switch to gradually increase the illumination intensity of the photoresistor, so as to display the number of the ammeterThe number of the voltmeter (above are all selected to be filled with "increase", "decrease" or "unchanged")

The problem solving method according to the utility model comprises the following specific steps:

judging the serial and parallel connection modes of the circuits, and judging the measuring objects of the ammeter and the voltmeter at the same time; the present embodiment is R and R ₀ The ammeter measures the power supply current and the voltmeter measures the voltage R of the resistor;

step two, as shown in fig. 13, the nine squares corresponding to the nine squares are drawn, and the physical quantity related to this embodiment is the resistance R ₀ Voltage U of (2) ₀ Current I ₀ Resistance R ₀ The method comprises the steps of carrying out a first treatment on the surface of the The voltage U, the current I and the resistor R of the resistor R; voltage U of power supply _{Total (S)} Main current I _{Total (S)} Total resistance R _{Total (S)} ；

Step three, filling the known physical quantity in the stem into the small square, the present embodiment is a problem that the dynamic circuit judges the change of the physical quantity, and the change physical quantity and the unchanged physical quantity information need to be judged according to the intention, and the known physical quantity is the resistor R ₀ Invariable, represented by triangles, supply voltage U _{Total (S)} Invariable, represented by triangles, photosensitive R becomes smaller, represented by downward arrows;

step four, checking whether each physical quantity accords with 'identity', 'simultaneity', 'unification';

fifthly, according to the serial-parallel connection mode of the circuit,and filling the corresponding physical quantity in the small square lattice by using the rules of current, voltage and resistance. The present embodiment is R ₀ And R, can be filled with the total resistance R _{Total (S)} The decrease is indicated by the downward arrow, current I ₀ The decrease is indicated by a downward arrow, the decrease in current I is indicated by a downward arrow, and the increase in voltage U is indicated by an upward arrow;

step six, utilizing ohm law formula and deformation formula

And solving the corresponding physics. Total current I in this embodiment _{Total (S)} The enlargement is indicated by an upward arrow, voltage U ₀ The enlargement is indicated by an upward arrow.

And step five and step six belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the process, the problems of the embodiment are completed, the voltmeter and the ammeter measuring object are directly marked in the table, the voltage representation number is reduced, the current representation number is increased, the problem difficulty is high, great help is provided for students to do problems and teacher problems, and the students are effectively helped to quickly and accurately complete problem solving.

Embodiment seven, a range of variation of the electrical physical quantity.

As shown in FIG. 14, the power supply is composed of three new dry batteries connected in series, and the resistor R is fixed ₁ Has a resistance of 5 omega, R ₂ The name plate of the slide rheostat is marked with the character of ' 20Ω 1A ', the measuring range of the ammeter is 0-0.6A, the measuring range of the voltmeter is 0-3V, and the safety of each circuit element is ensured when the slide sheet of the slide rheostat is moved, which is correctly () ' in the following description.

A. The current representation number allows a range of variation from 0.2A to 0.6A.

B. The voltage representation number allows a range of variation of 0-3V.

C. Resistor R ₁ The allowable variation range of the consumed power is 0.45W-1.8W.

D. Varistor R ₂ The resistance of the access circuit is allowed to vary from 2.5 omega to 10 omega.

The problem solving method according to the utility model comprises the following specific steps:

the first basis is to judge the serial and parallel connection modes of the circuits and judge the measuring objects of the ammeter and the voltmeter. The present embodiment is R ₁ And R is ₂ Is a series circuit of (1) and a voltmeter R ₂ A voltage.

And secondly, drawing corresponding small grids, wherein the problem adopts twelve grids. The physical quantities referred to in the examples are written into the small square.

Thirdly, filling the known physical quantity in the stem into the small square lattice. The known physical quantity of this embodiment is R ₁ =5Ω、U _{Total (S)} In this case, only 2 physical quantities are known, and the conditions of 3 different rows of physical quantities are not satisfied, so that R needs to be determined according to the topic ₂ When R is a maximum or minimum of ₂ Minimum time min, can infer R _{Total (S)} min，I _{Total (S)} max, from the range 0-0.6A of the ammeter, see I _{Total (S)} =0.6a is brought into a small square as a known amount.

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

And fifthly, filling corresponding physical quantities in the small square lattice according to the series connection form of the circuit by utilizing the rules of current, voltage and resistance. The subject matter is R ₁ And R is ₂ Can be filled with I ₁ =0.6A，I ₂ =0.6A，U ₂ =1.5v. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Sixth, ohm law formula and deformation formula are utilized

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Voltage U in the present embodiment (modification) ₁ =3V，R ₂ =2.5Ω，P ₁ =1.8w. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Through the above-mentioned passingSolving the maximum value of 0.6A, the minimum value of 1.5V and the resistance R of the ammeter ₂ The minimum value of (2.5 omega), the electric power P ₁ The minimum value is 1.8W, the problem is a choice problem, the choice problem can remove the sequential process of labeling and solving each physical quantity, and the problem solving speed can be improved.

The utility model is applied to the problem again, and the small square is drawn again to fill in the corresponding physical quantity.

First, known physical quantities in the stem are filled into small squares. The known physical quantity of this embodiment is R ₁ =5Ω、U _{Total (S)} In this case, only 2 physical quantities are known, and the conditions of 3 different rows of physical quantities are not satisfied, so that R needs to be determined according to the topic ₂ A maximum or minimum induced variation of (2); when R is ₂ Max, can be inferred R _{Total (S)} max，I _{Total (S)} min，I ₁ min，I ₂ min, U can be seen ₁ min，U ₂ max, voltmeter measurement R ₂ Voltage according to the question U ₂ Maximum 3V is brought into the grid as a known condition.

In the second check, whether or not the physical quantities match "identity", "simultaneity" or "uniformity".

And thirdly, filling corresponding physical quantities in the small square lattice according to the series connection form of the circuit by utilizing the rules of current, voltage and resistance. The subject matter is R ₁ And R is ₂ Can be filled with I ₂ =0.3A，I _{Total (S)} =0.3A，U ₁ =1.5v. (the second step and the third step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Sixth, ohm law formula and deformation formula are utilized

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Current I in this embodiment ₁ =0.3A，R ₂ =10Ω，P ₁ =4.5w. (the second step and the third step belong to sister steps, and the following is carried out according to the requirementsOrderly adjustment and recycling).

Through the process, the minimum value 0.3A, the maximum value 3V and the resistance R of the ammeter are solved ₂ Maximum value 10Ω, electric power P ₁ The maximum value is 4.5W, the problem is a choice problem, the choice problem can remove the sequential process of labeling and solving each physical quantity, and the problem solving speed can be improved.

The eighth embodiment is to calculate the resistance by a special method.

As shown in FIG. 15, in the experiment of "voltammetric resistance", R can also be measured by the circuit shown in the figure if the voltmeter is damaged _x The resistance of the sliding rheostat R is known as R ₀ The specific experimental steps are as follows:

a. the sliding sheet of the sliding rheostat is moved to the rightmost end, and the indication I of the ammeter is read out ₁ ;

b. The sliding sheet of the sliding rheostat is moved to the leftmost end, and the indication I of the ammeter is read out ₂ ;

Expression of fixed-value resistor R _x =。

The problem solving method according to the utility model comprises the following specific steps:

first, the serial and parallel connection modes of the circuit are judged according to the questions, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In this embodiment, the switch S is closed, the slide sheet of the slide rheostat is moved to the rightmost end, and the slide rheostat has the largest resistance value, namely the resistor R _x And resistance R _{Sliding device} The current meter measures the supply current.

Second, as shown in fig. 15, a square is drawn corresponding to the square. The physical quantity related to the embodiment is the resistance R _x Voltage U of (2) _x Current I _x Resistance R _x The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of resistor R _{Sliding device} Current I _{Sliding device} Resistance R _{Sliding device} The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} 。

Third, the known physical quantity R in the present embodiment is known _{Sliding device} Is R ₀ 、I _{Total (S)} Is I ₁ Assuming a constant value resistor Rx resistanceKnown as Rx.

Fourth, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection mode of the circuit by utilizing the rules of current, voltage and resistance. The present embodiment is a resistor R _x Parallel circuit with resistor R, can be filled with current I _{Sliding device} Is I ₁ ，U _{Total (S)} Is R _x I ₁ +R ₀ I ₁ 。

Sixth, using ohm's law equation and deformation equation

And solving the corresponding physics. Can solve U _{Sliding device} Is R ₀ I ₁ Can solve U _x Is R _x I ₁ 。

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements.

The utility model is applied to the problem again, firstly, the serial and parallel connection forms of the circuits are judged according to the problem, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In this embodiment, the switch S is closed, the sliding sheet of the sliding rheostat moves to the leftmost end, the resistance value of the sliding rheostat is 0, and the sliding rheostat is a single-connection circuit of the resistor Rx, and the ammeter measures the power supply current.

Second, as shown in fig. 15, a square is drawn corresponding to the square. The physical quantity related to the embodiment is the resistance R _x Voltage U of (2) _x Current I _x Resistance R _x The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of resistor R _{Sliding device} Current I _{Sliding device} Resistance R _{Sliding device} The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} 。

Third, the known physical quantity R in the present embodiment is known _{Sliding device} Is 0, I _{Total (S)} Is I ₂ Let Rx be the resistance of the constant resistor Rx.

Fourth, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Fifthly, filling corresponding physical quantities in the small square lattice according to the series-parallel connection mode of the circuit by utilizing the rules of current, voltage and resistance. The present embodiment is a resistor R _x Single-connection circuit capable of filling current U _{Sliding device} 0,U of a shape of 0,U _{Total (S)} Is R _x I ₂ 。

Sixth, using ohm's law equation and deformation equation

And solving the corresponding physics. Can solve U _x Is R _x I ₂ 。

The fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to requirements. Through the above process, U can be found _{Total (S)} =R _x I ₂ ，U _{Total (S)} =R _x I ₁ +R ₀ I ₁ Deducing R _x I ₂ =R _x I ₁ +R ₀ I ₁ And solving an expression of Rx to finish the problem solving. The problem is blank filling, the sequential process of labeling and solving each physical quantity can be removed, the problem solving speed can be improved, the problem difficulty is high, and great help is provided for students to do problems and teachers to teach.

Example nine, specific method to power rating.

As shown in fig. 16, the R resistance value in the circuit is known, and the rated power of the small bulb with the rated voltage of "3.8V" can be measured by a voltmeter.

The problem solving method according to the utility model comprises the following specific steps:

first, the serial and parallel connection modes of the circuit are judged according to the questions, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In the embodiment, the switch S, S1 is closed, the sliding rheostat is connected with the fixed value resistor in series, and the ammeter measures the power supply current; in the embodiment, the switch S, S2 is closed, the slide rheostat is connected with the bulb in series, and the ammeter measures the power supply current; in this embodiment, the switches S, S1 and S2 are closed, and the fixed resistor is connected in parallel with the bulb and then connected in series with the sliding rheostat, which belongs to a series-parallel circuit, and the ammeter measures the power supply current.

Second, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Second, as shown in fig. 16, a twelve square lattice is drawn, corresponding to the twelve square lattice. The embodiment requires measuring rated power of a 3.8V bulb, and the physical quantities involved are voltage U, current I and resistance R of a resistor R, and electric power P; voltage U of resistor R _{Lamp with light-emitting device} Current I _{Lamp with light-emitting device} Resistance R _{Lamp with light-emitting device} Electric power P _{Lamp with light-emitting device} The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} Total electric power P _{Total (S)} 。

Third, the known physical quantity in the stem is filled into the small square lattice, the known physical quantity fixed resistor R is known, and the rated voltage U of the bulb is set _{Lamp with light-emitting device} Is known.

Fourth, in combination with the "simultaneity" of the present embodiment, it was found that the bulb voltage could not be made 3.8V by means of a constant resistance and ammeter. Therefore, the A option is only 2 known conditions, the requirement of using twelve grids cannot be met, and the rated power at the rated voltage of 3.8V cannot be solved, so that the A option is a wrong option.

The present utility model is again applied to this problem;

first, the serial and parallel connection modes of the circuit are judged according to the questions, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In the embodiment, the switch S, S1 is closed, the fixed value resistor is connected in parallel with the bulb and then connected in series with the sliding rheostat, and the fixed value resistor belongs to a series-parallel circuit, and the ammeter measures the bulb current; in this embodiment, the switch S, S is closed, the fixed resistor is connected in parallel with the bulb and then connected in series with the sliding rheostat, which belongs to a series-parallel circuit, the ammeter measures the power supply current, in this embodiment, the switches S, S1 and S2 are closed, the fixed resistor is connected in parallel with the bulb and then connected in series with the sliding rheostat, which belongs to a series-parallel circuit, and the ammeter does not work.

Second, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Second, as shown in fig. 16, a twelve square lattice is drawn, corresponding to the twelve square lattice. This example requires measuring the rating of a 3.8V bulbThe electric rate, the physical quantity involved is the voltage U, current I, resistance R, electric power P of resistance R; voltage U of resistor R _{Lamp with light-emitting device} Current I _{Lamp with light-emitting device} Resistance R _{Lamp with light-emitting device} Electric power P _{Lamp with light-emitting device} The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} Total electric power P _{Total (S)} 。

Third, the known physical quantity in the stem is filled into the small square lattice, the known physical quantity fixed resistor R is known, and the rated voltage U of the bulb is set _{Lamp with light-emitting device} Is known.

Fourth, in combination with the "simultaneity" of the present embodiment, it was found that the bulb voltage could not be made 3.8V by means of a constant resistance and ammeter. Therefore, only 2 known conditions of the B option cannot meet the requirement of using twelve grids, and the rated power at the rated voltage of 3.8V cannot be solved, so the B option is an error option.

The present utility model is again applied to this problem;

first, the serial and parallel connection modes of the circuit are judged according to the questions, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In the embodiment, the switch S, S1 is closed, the fixed resistor is connected in parallel with the bulb and then connected in series with the slide rheostat, and the fixed resistor belongs to a series-parallel circuit, and the ammeter measures resistance current; in this embodiment, the switch S, S is closed, the fixed resistor is connected in parallel with the bulb and then connected in series with the sliding rheostat, which belongs to a series-parallel circuit, the ammeter measures the power supply current, in this embodiment, the switches S, S1 and S2 are closed, the fixed resistor is connected in parallel with the bulb and then connected in series with the sliding rheostat, which belongs to a series-parallel circuit, and the ammeter does not work.

Second, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Second, as shown in fig. 16, a twelve square lattice is drawn, corresponding to the twelve square lattice. The embodiment requires measuring rated power of a 3.8V bulb, and the physical quantities involved are voltage U, current I and resistance R of a resistor R, and electric power P; voltage U of resistor R _{Lamp with light-emitting device} Current I _{Lamp with light-emitting device} Resistance R _{Lamp with light-emitting device} Electric power P _{Lamp with light-emitting device} The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} Total ofElectric power P _{Total (S)} 。

Third, the known physical quantity in the stem is filled into the small square lattice, the known physical quantity fixed resistor R is known, and the rated voltage U of the bulb is set _{Lamp with light-emitting device} Is known.

Fourth, in combination with the "simultaneity" of this embodiment, the bulb and the fixed resistor are in parallel connection, the voltage of the bulb is equal to the voltage of the fixed resistor, when S, S1 is closed, the sliding rheostat is moved to make the multiplication of the current value measured by the ammeter and the resistance value of the fixed resistor equal to 3.8V, by means of the rule that the parallel branch voltages are equal, the bulb can normally emit light, the position of the sliding rheostat is kept unchanged, S, S is closed, and the ammeter measures the trunk current I _{Total (S)} . At this time, it was found that there are 4 known physical quantities in the twelve grids, and at least 3 conditions for the known physical quantities are required to meet the requirement of using the twelve grids, and the rated power at the rated voltage of 3.8V can be experimentally measured, so option C is the correct option.

The present utility model is again applied to this problem;

first, the serial and parallel connection modes of the circuit are judged according to the questions, and the measuring objects of the ammeter and the voltmeter are judged at the same time. In the embodiment, the switch S, S1 is closed, the slide rheostat is connected with the bulb in series, and the ammeter measures the power supply current; in this embodiment, the switch S, S is closed, the fixed resistor is connected in series with the sliding rheostat, the ammeter measures the power supply current, in this embodiment, the switches S, S and S2 are closed, the sliding rheostat is connected singly, and the ammeter does not work.

Second, it is checked whether each physical quantity matches "identity", "simultaneity" or "uniformity".

Second, as shown in fig. 16, a twelve square lattice is drawn, corresponding to the twelve square lattice. The embodiment requires measuring rated power of a 3.8V bulb, and the physical quantities involved are voltage U, current I and resistance R of a resistor R, and electric power P; voltage U of resistor R _{Lamp with light-emitting device} Current I _{Lamp with light-emitting device} Resistance R _{Lamp with light-emitting device} Electric power P _{Lamp with light-emitting device} The method comprises the steps of carrying out a first treatment on the surface of the Voltage U of power supply _{Total (S)} Current I of power supply _{Total (S)} Total resistance R _{Total (S)} Total electric power P _{Total (S)} 。

Third, the stem is processedThe known physical quantity is filled into small square lattice, the known physical quantity fixed resistor R is known, and the rated voltage U of the bulb is known _{Lamp with light-emitting device} Is known.

Fourth, in combination with the "simultaneity" of the present embodiment, it was found that the bulb voltage could not be made 3.8V by means of a constant resistance and ammeter. Therefore, only 2 known conditions of the D option cannot meet the requirement of using the twelve grid, and the rated power at the rated voltage of 3.8V cannot be solved, so the D option is a wrong option.

The problems are selected problems, the sequential process of labeling and solving each physical quantity can be removed from the selected problems, the problem solving speed can be improved, the problem solving difficulty is high, and great help is provided for students to do problems and teachers to teach.

Embodiment ten, judge the table data error.

As shown in FIG. 17, when the Ming's college study on the relation between current and voltage, the devices were prepared, wherein the power supply voltage was 4.5V and remained unchanged, the ammeter (0-0.6A), the voltmeter (0-3V), the sliding rheostat (20Ω, 1A), the fixed resistor 5 Ω, the switch, and the wires. Experiments were performed according to the circuit diagram as shown in the figure:

(1) After the calculation, the small euphoria is measured by the sliding sheet P of the book-adjusting sliding rheostat to obtain different currents and corresponding voltages passing through the fixed resistor R, and the different currents and the corresponding voltages are shown in the table: the experimental operation of the xiaoxin is not standard after the beam teacher sees the xiaoxin data, one group of data is compiled by the beam teacher, and the basis for explaining the judgment of the beam teacher is 。

The problem solving method according to the utility model comprises the following specific steps:

the first basis is to judge the serial and parallel connection modes of the circuits and judge the measuring objects of the ammeter and the voltmeter. Examples are R and R _{Sliding device} The voltmeter measures the voltage of the resistor R.

And secondly, drawing corresponding small squares, wherein the problem adopts a nine square lattice. The physical quantities referred to in the examples are written into the small square.

Thirdly, filling the known physical quantity in the stem into the small square lattice. The physical quantity known in the examples is r=5Ω, U _{Total (S)} =4.5V, where only 2 physical quantities are known, not satisfying the known 3 different column physical quantitiesThe amount condition is that error data needs to be determined according to the questions, and the first set of data or the last set of data is generally taken as a known condition, and the first set of data is taken as the known condition into a table u=0.5v, i=0.1a in this embodiment.

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

And fifthly, filling corresponding physical quantities in the small square lattice according to the series connection form of the circuit by utilizing the rules of current, voltage and resistance. The subject matter is R and R _{Sliding device} Can be filled with I _{Sliding device} =0.1A，U _{Sliding device} =4v. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Sixth, ohm law formula and deformation formula are utilized

And solving the corresponding physics. R in this example _{Sliding device} =40Ω. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Through the above process, R is solved _{Sliding device} =40Ω, which is greater than 20Ω maximum given by the stem, the first set of data belongs to the faking. The embodiment is an experiment question, the experiment question can remove the sequential process of labeling and solving each physical quantity, and the question solving speed can be improved.

In the eleventh embodiment, the slide rheostat specification selection is determined.

As shown in fig. 18, a small lamp labeled with the word "3.8V" was found in the young student's hand, she wanted to know the resistance of the lamp when it was working normally, and then found some equipment in the school laboratory wanted to test, with a constant supply voltage of 6V.

(1) The sliding rheostat is regulated to make the small bulb emit light normally, and the current meter has the number as shown in figure BA, the resistance of the small bulb in normal operation is；

(2) In the experiment, two sliding varistors, namely a sliding varistor A of 10 omega and 0.5A and a sliding varistor B of 5 omega and 1A, are respectively, and ___ (filled with A or B) sliding varistors are selected for completing the experiment.

The problem solving method according to the utility model comprises the following specific steps:

the first basis is to judge the serial and parallel connection modes of the circuits and judge the measuring objects of the ammeter and the voltmeter. An example is a series circuit of a small bulb L and a sliding varistor resistor R, with a voltmeter measuring the voltage of the small bulb L.

And secondly, drawing corresponding small grids, wherein the problem adopts twelve grids. The physical quantities referred to in the examples are written into the small square.

Thirdly, filling the known physical quantity in the stem into the small square lattice. Example problem known physical quantity is U _L =3.8V、I _L =0.38A, U total=6v.

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

And fifthly, filling corresponding physical quantities in the small square lattice according to the series connection form of the circuit by utilizing the rules of current, voltage and resistance. The series circuit of the bulb L and the resistor R of the slide rheostat can be filled with I _{Sliding device} =0.38A，U _{Sliding device} =2.2v. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Sixth, ohm law formula and deformation formula are utilized

And solving the corresponding physics. In examples R _{Sliding device} =5.79 Ω. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Through the above process, R is solved _{Sliding device} The maximum value of a sliding rheostat is 5 Ω, the maximum value of B sliding rheostat is 10 Ω, and thus B sliding rheostat meets the subject. The problem is an experiment problem, the experiment problem can remove the sequential process of labeling and solving each physical quantity, and the problem solving speed can be improved.

Embodiment twelve, multi-gear problem.

As shown in fig. 19, an internal circuit diagram of a four-gear electric heater is shown. Rotary switchAs shown in the figure, the metal contacts (1), (2), (3) and (4) are respectively connected with the first figures (1, 2, 3 and 4), and two ends of the rotating handle are respectively provided with a metal sliding sheet, so that two adjacent contacts can be connected, and the rotary switch is made of insulators except the metal contacts and the metal sliding sheets. The rotary switch has four gears A, B, C, D, such as D gear, one end of the metal sliding sheet is connected with the two contacts (1) and (2), the other end of the metal sliding sheet is connected with the two contacts (3) and (4), and the gear is determined according to the second image (the four gears are respectively named as high-temperature gear, medium-temperature 1 gear, medium-temperature 2 gear and low-temperature gear). Of the four-stage heating powers, the D-stage circuit has a heating power of 100W and R ₂ =4R ₁ (the power supply voltage is 220V, and the resistance of the heating wire remains unchanged):

(1) R when the rotary switch is positioned at the A gear ₁ And R is ₂ Is that(optionally "series" or "parallel") the total current in the circuit isA?

(2) R in low temperature gear ₁ What is the electric power of?

(3) The heating efficiency of the electric heater is 80%, and what is the time required to heat 1kg of water at an initial temperature of 20 ℃ to 42 ℃ by using a low temperature range?

The problem solving method according to the utility model comprises the following specific steps:

the first basis is to judge the serial and parallel connection modes of the circuits and judge the measuring objects of the ammeter and the voltmeter. Example high temperature gear is R ₁ And R is ₂ Is provided.

And secondly, drawing corresponding small grids, wherein the problem adopts twelve grids. The physical quantities referred to in the examples are written into the small square.

Thirdly, filling the known physical quantity in the stem into the small square lattice. Example known physical quantity is P _{Total (S)} =100W、U _{Total (S)} In this case, only 2 physical quantities are known, and the conditions of 3 different rows of physical quantities are not satisfied, so R needs to be determined according to the topic ₂ =4R ₁ Inferable P ₁ =4P ₂ ，P ₁ =80W，P ₂ =20W。

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

And fifthly, filling corresponding physical quantities in the small square lattice according to the parallel connection form of the circuit by utilizing the rules of current, voltage and resistance. Examples are R ₁ And R is ₂ Can be filled with U ₁ =220V，U ₂ =220v. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Sixth, ohm law formula and deformation formula are utilized

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Voltage +.>

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，R ₁ =605Ω，R ₂ =2420Ω. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

The utility model is applied to the embodiment again, and the first basis is to judge the serial and parallel connection modes of the circuit and judge the measuring objects of the ammeter and the voltmeter at the same time. The switch of the embodiment rotates to the position A, and the circuit belongs to a low-temperature gear and is R ₁ And R is ₂ Is provided.

And secondly, drawing corresponding small grids, wherein twelve grids are adopted in the embodiment. The physical quantities referred to in the examples are written into the small square.

Thirdly, filling the known physical quantity in the stem into the small square lattice. Examples the known physical quantity is R ₁ =605Ω，R ₂ =2420Ω，U _{Total (S)} =220V。

Fourth, it is checked whether or not the physical quantities match "identity", "simultaneity" and "uniformity".

Fifthly, according to the parallel connection form of the circuit, the corresponding physical quantity in the small square lattice is fed by utilizing the rules of current, voltage and resistanceAnd (5) filling rows. Examples are R ₁ And R is ₂ Can be filled with R _{Total (S)} =3025Ω，I ₁ =0.073A. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

Sixth, ohm law formula and deformation formula are utilized

Electric power calculation formula and deformation formula +.>

And solving the corresponding physics. Voltage I in the examples _{Total (S)} =0.073A，U ₁ =44V，P ₁ =3.2w. (the fifth step and the sixth step belong to sister steps, and are sequentially adjusted and recycled according to the requirements).

The process solves the total current of the first small problem 0.073A and the second small problem R ₁ The electric power of 3.2W of the system is the calculation problem, the sequential process of solving each physical quantity is noted in the small square, the students can be effectively helped to complete the solving process rapidly and accurately, sequential marks are reserved for writing the problem solving process, and learning can be completed efficiently.

Claims (3)

1. A physical problem solving plate for junior middle school applying ohm's law and electric power is rectangular or square, and comprises a bottom plate, a frame and a groove, wherein the bottom plate is externally provided with a frame, and the groove is arranged in the frame; the method is characterized in that: when the problem solving plate is square, setting a nine-square lattice, setting the nine-square lattice as nine small squares, and placing the nine small squares in the groove; when the problem solving plate is rectangular, setting a twelve-square lattice, setting the twelve-square lattice as twelve small squares, and placing the twelve small squares in the groove;

One surface of the groove bottom plate is provided with a line, and the line is drawn into nine small squares or twelve small squares, so that the small squares are conveniently placed in the groove;

the left and right sides of the frame on the same surface as the groove are provided with a certain area, and a plurality of formulas are drawn on the area of the frame.

2. The junior middle school physical problem solving board applying ohm's law and electric power according to claim 1, wherein: when the solving plate is square, nine physical quantities are respectively carved on the nine small squares, the nine physical quantities respectively comprise three voltage values, three current values and three resistance values, and the voltage values are U respectively ₁ 、U ₂ And U _{Total (S)} The current values are respectively I ₁ 、I ₂ And I _{Total (S)} The resistance values are R respectively ₁ 、R ₂ And R is _{Total (S)} 。

3. The junior middle school physical problem solving board applying ohm's law and electric power according to claim 1, wherein: when the solving plate is rectangular, twelve physical quantities are respectively marked on twelve small squares, and each physical quantity comprises three voltage values, three current values, three resistance values and three power values, wherein the voltage values are U respectively ₁ 、U ₂ And U _{Total (S)} The current values are respectively I ₁ 、I ₂ And I _{Total (S)} The resistance values are R respectively ₁ 、R ₂ And R is _{Total (S)} The power values are P respectively ₁ 、P ₂ And P _{Total (S)} 。

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