CN104217633A

CN104217633A - Quantitative coulomb law demonstrating scheme

Info

Publication number: CN104217633A
Application number: CN201310221476.3A
Authority: CN
Inventors: 李忠相
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-05-30
Filing date: 2013-05-30
Publication date: 2014-12-17

Abstract

The invention provides a quantitative coulomb law demonstrating scheme, and belongs to the field of physics teaching experiments. According to the quantitative coulomb law demonstrating scheme, circular silver paper fixed on an organic glass support serves as electrified bodies, an electronic analytical balance serves as a measuring tool, the quantity of electric charge is controlled by a contact dichotomy, and the distance between the electrified bodies is controlled by a fixing device. During experiment, one of the electrified bodies is placed on a testing table of the electronic analytical balance, the other electrified body is fixed on a support above the analytical balance, and the two electrified bodies face to each other in parallel. The coulomb force between the electrified bodies can be obtained by pressure applied to the measuring and testing table of the electronic analytical balance. In the scheme, the acting force between the electrified bodies, the quantity of electric charge of the electrified bodies and the relation between the distances of the electrified bodies can be obviously demonstrated quantitatively by using a control variable experimenting method. By the quantitative coulomb law demonstrating scheme, classroom demonstration experiments can be carried out in physics teaching of middle schools and colleges, and student experiments can also be carried out in teaching of college physics experiments.

Description

Coulomb law quantitatively demonstrates scheme

Technical field

The present invention relates to Coulomb law and quantitatively demonstrate scheme, belong to physics teaching experiment field.

Background technology

The quantitative experiment of Coulomb law, operates succinctly and measuring accuracy height is successful key.

The quantitative experiment of Coulomb law, in scientific research, measuring accuracy is very high, but its experimental principle and method are all very complicated, can not be used for teaching demonstration.

Experiment for quantitatively demonstrating Coulomb law mainly contains two large classes.One is known Coulomb balance, and mainly through the Coulomb force equalising torque that torsional moment wiry and electric globule are subject to, the angle turned over by tinsel is to reflect the size of Coulomb force; Two is experiments that some Physical Education Teacher used some autonomous Design in open class at different levels, and the angle of putting after the electrified body mainly through hanging is subject to Coulomb force reflects the size of Coulomb force.This two large classes experiment is succinct all not, and its electrified body reaches equilibrium state a new position after being subject to Coulomb force effect, in order to measure or control the distance between two electrified bodys, will regulate gradually its equilibrium position.In the adjustment process of long period, the quantity of electric charge of electrified body can reduce gradually, increases experimental error.Meanwhile, Equations of The Second Kind experimental program precision is generally on the low side, can only obtain rough result, and comparatively large by such environmental effects, on-the-spot demonstration success ratio is lower.

Summary of the invention

The object of this invention is to provide a kind of operation succinct, the quantitative lecture experiment scheme of the Coulomb law that measuring accuracy is high.By test, five groups of experimental datas can be obtained in 20 seconds; Data precision is high, can meet Coulomb law exactly.

This programme circular masking foil be fixed on organic glass support makes electrified body, makes survey instrument with electronic analytical balance, controls charged volume charge amount with contact dichotomy, controls electrified body spacing by stationary installation.During experiment, first make two electrified bodys charged by equipment such as electrizers.After an electrified body is placed in electronic analytical balance test board, then balance registration is returned to zero.Another electrified body is fixed on analytical balance overhead support by stationary installation, makes two electrified bodys parallel just right.If two electrified body band like charges, balance display registration be on the occasion of; If two electrified body band xenogenesis electric charges, balance display registration is negative value.The Coulomb force between two electrified bodys can be obtained by unit conversion.Keep the two electrified body quantities of electric charge constant, regulate the distance between them, observe and record the change of Coulomb force.Keep the distance of two electrified bodys constant, change the quantity of electric charge of one of them electrified body by contact dichotomy, observe and record the change of Coulomb force.Finally by data processing, quantitatively draw the relation of Coulomb force F and quantity of electric charge q and electric charge spacing r.

Accompanying drawing explanation

Fig. 1 is electrified body 1 and supporting structure schematic diagram thereof

Fig. 2 is electrified body 2 and supporting structure schematic diagram thereof

Fig. 3 is tinfoil paper disk 3 and supporting structure schematic diagram thereof

Fig. 4 is stationary installation schematic diagram

Fig. 5 is experiment one-piece construction schematic diagram

Fig. 6 is the F-1/r drawn by test data ²graph of a relation

Fig. 7 is the F-q drawn by test data ₁graph of a relation

In figure: 1. electrified body 1,2. electrified body 2,3. tinfoil paper disk 3,4. insulating support, 5. distance scale, 6. fixed frame, 7. test tube clamp, 8. electronic analytical balance, 9. cloche, 10. electronic analytical balance test board, 11. action buttons, 12. registration display screens, 13. springs, 14. spacing holes

Embodiment

The masking foil disk of electrified body 1 (1), electrified body 2 (2) and tinfoil paper disk 3 (3) to be all diameters be 4cm, is bonded on the support (4) made with organic glass with glue.Distance scale (5) by centimetre in units of, for making scale eye-catching, redness can be sprayed into every lattice.Fixed frame (6) is made with timber or organic glass, and size is as the criterion with the top of analytical balance cloche.Stationary installation (as Fig. 4) is formed with half test tube clamp (7) and fixed frame (6).Electronic analytical balance (8) precision selects 0.001g to get final product (precision 0.0001g is better), and top carries cloche (9).Registration display screen (12) display numeral is less and angle is unfavorable for student's reading, when the program is used as Demonstrating, by camera or projector for real object, its registration is projected to giant-screen.Spacing hole (14) size should slightly larger than the size of insulating support (4), and its position should ensure that electrified body 2 (2) standing back is directly over balance test board (10).

Experimental procedure:

A. by electronic analytical balance (8) adjustment level, switch on power, open measurement function, registration returns to zero;

B. the electrified body 1 (1) of a certain amount of electric charge of band is put to balance test board (10) together with insulating support, observe registration change, then by action button (11), registration is returned to zero;

C. the electrified body 2 (2) of a certain amount of like charges of band is fixed on above cloche together with insulating support, allows two charged metal disks just to (as shown in Figure 5);

D. regulate the position of electrified body 2 (2), allow two electrified body spacings be respectively 4cm, 5cm, 6cm ..., observe and record data (measured data is in table 1);

E. fix the position of electrified body 2 (2), remove after uncharged tinfoil paper disk 3 (3) is contacted with electrified body 1 (1), the quantity of electric charge of electrified body 1 (1) is reduced by half, observes and record data;

F. allow the quantity of electric charge of electrified body 1 (1) successively reduce by half by the method in step e again after allowing tinfoil paper disk 3 (3) discharge, observe and record data (measured data is in table 2);

G. data (test result as shown in Figure 6, Figure 7) are analyzed by graphing method;

H. experiment equipment is arranged.

The relation of table 1 electric charge intermolecular forces F and electric charge spacing r

Table 2 electric charge intermolecular forces F and quantity of electric charge q ₁relation (r=4cm)

Claims

1. a quantitative demonstration scheme for Coulomb law, belongs to physics teaching experiment field.This programme circular masking foil be fixed on organic glass support makes electrified body, makes survey instrument with electronic analytical balance, controls charged volume charge amount with contact dichotomy, controls electrified body spacing by stationary installation.During experiment, an electrified body is placed in electronic analytical balance test board, and another electrified body is fixed on analytical balance overhead support, makes two electrified bodys parallel just right.Utilize the pressure that electronic analytical balance measurement test board is subject to, thus obtain the Coulomb force between electrified body.By control variable experimental technique, the relation between the acting force quantitatively between demonstration electrified body and the quantity of electric charge of electrified body and the distance of electrified body.

2. Coulomb law according to claim 1 quantitatively demonstrates scheme, it is characterized in that: electrified body in an experiment position is fixed, and measured electrified body reaches stress balance at same position all the time, and another electrified body is by its position of stationary installation manual control.

3. Coulomb law according to claim 1 quantitatively demonstrates scheme, it is characterized in that: change Coulomb force being changed into measured electrified body and other object intermolecular forces, and is directly measured by the instrument of high-precision dynamometry (or quality).