Coulomb's law teaching demonstration experiment device

Abstract

The invention discloses a Coulomb's law teaching demonstration experiment device, and relates to the technical field of Coulomb's law experiments, the Coulomb's law teaching demonstration experiment device comprises an insulating part, a metal sheet and an electronic balance, the metal sheet is located right above a tray of the electronic balance, one end of the insulating part is connected with one end, away from the electronic balance, of the metal sheet, and the tray of the electronic balance is a metal tray. The metal tray is grounded; after the metal sheet is electrified, the grounded metal tray of the electronic balance induces electrification, and the electronic balance starts to display the numerical value of coulomb force; the distance between the metal sheet and the grounding metal tray of the electronic balance is adjusted through the insulating part, the change relation among the electric quantity, the distance and the Coulomb force can be obtained, and therefore the Coulomb law teaching demonstration experiment is completed, that is, only the metal sheet needs to be electrified, the operation time is saved, the experiment efficiency is improved, and meanwhile the experiment efficiency is improved. And moreover, the electronic balance can directly display the coulomb force, so that experimental data are convenient to observe.

Description

Technical Field

[0001] The invention relates to the technical field of Coulomb's law experiments, in particular to a Coulomb's law teaching demonstration experimental device. Background Art

[0002] At present, physics textbooks give two experimental schemes to demonstrate Coulomb's law. One of them is a qualitative exploration demonstration experimental scheme based on the control variable method: this demonstration experiment allows the charged body C and the pendulum ball to carry the same charge, changes the distance r between the charged body C and the pendulum ball, observes the change in the angle between the electrostatic pendulum and the plumb line, and analyzes the change in the Coulomb force F, and derives the qualitative relationship between F and r. When qualitatively exploring the relationship between the Coulomb force F and the amount of charge, the angle θ of the electrostatic pendulum deviation is observed by changing the amount of charge carried by the charged body, thereby analyzing the relationship between F and θ. However, this method has certain limitations. First, the deflection angle of the thin rope is small, and the experimental phenomenon is not obvious. Second, the hanging ball is unstable and easily disturbed to form a conical pendulum. The deflection angle is constantly changing, which is not conducive to observation.

[0003] Another experimental device given in the textbook is the Coulomb torsion balance, which aims to guide students to conduct quantitative research on the relationship between electric field force, charge and distance. When using this experimental device for demonstration, there are mainly the following problems: First, the experimental operation is difficult, and a slight disturbance can affect the experimental process and reduce the accuracy of the observed data; Second, although in the case of a relatively small torsion angle, it can be approximately considered that the distance between the center of the sphere and sin2 a Proportional to the distance, in order to ensure that this prerequisite is met, the difficulty of the demonstration experiment is further increased; third, point charge is an idealized model, which is difficult to reproduce in an experimental environment. In an air environment, the relationship between the charge of the charged sphere and the radius r of the charged sphere is relatively complicated. When the radius r is reduced, the charge of the sphere is also smaller, and the Coulomb force is not obvious; when the radius r of the charged sphere is close to the distance, it is affected by the electrostatic force, and the charge distribution is no longer uniform. The distance between the charges cannot be represented by the distance between the centers of the spheres, which increases the difficulty of the experiment; fourth, the charge leakage process is very fast, the operation is difficult, and the reading of the measurement data is unstable. The instrument is small, the visual effect of the experimental results is poor, and it is very difficult for students to operate independently, which makes it difficult to stimulate students' interest in further exploration.

[0004] Therefore, people are in urgent need of a Coulomb's law teaching demonstration experimental device that is easy to operate and has experimental data that is easy to observe. Summary of the invention

[0005] The purpose of the present invention is to provide a Coulomb's law teaching demonstration experimental device to solve the problems existing in the above-mentioned prior art. Coulomb's law experiment can be carried out using a metal sheet and a metal tray of an electronic balance, which is more convenient to operate and the experimental data is easy to observe.

[0006] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention provides a Coulomb's law teaching demonstration experimental device, comprising an insulating member, a metal sheet and an electronic balance, wherein the metal sheet is located directly above the tray of the electronic balance, one end of the insulating member is connected to an end of the metal sheet away from the electronic balance, the tray of the electronic balance is a metal tray, and the metal tray is grounded.

[0007] Preferably, the metal sheet and the metal tray are both disc-shaped structures.

[0008] Preferably, the metal sheet and the outer surface of the metal tray are smoothly arranged.

[0009] Preferably, the Coulomb's law teaching demonstration experimental device also includes a lifting platform and a support frame, one end of the support frame is connected to the insulating member, and the other end is placed on the lifting platform.

[0010] Preferably, the lifting platform is a manual lifting platform.

[0011] Preferably, the Coulomb's law teaching demonstration experimental device also includes an airtight box, the top cover of the airtight box is detachable, the top cover of the airtight box is provided with a through hole for the insulating member to extend into, the insulating member is vertically arranged to the top cover of the airtight box, and the metal sheet and the electron microscope are located inside the airtight box.

[0012] Preferably, scale lines are provided on the insulating member, or a scale is connected to the insulating member.

[0013] Preferably, the Coulomb's law teaching demonstration experimental device also includes a heater for heating the airtight box.

[0014] Preferably, the airtight box is an acrylic airtight box.

[0015] Preferably, the Coulomb's law teaching demonstration experimental device also includes an electrostatic charging rod for electrifying the metal sheet.

[0016] Compared with the prior art, the present invention mainly achieves the following technical effects:

[0017] After the metal sheet is electrified by the electrostatic electrification rod, the metal sheet is close to the grounded metal tray of the electronic balance, the grounded metal tray of the electronic balance is electrified by induction, and the electronic balance begins to display the value of the Coulomb force; by adjusting the distance between the metal sheet and the grounded metal tray of the electronic balance through the insulating member, the changing relationship between the electric quantity, the distance and the Coulomb force can be obtained, thereby completing the Coulomb's law teaching demonstration experiment, that is, in this device, only the metal sheet needs to be electrified, compared with the two electrifications of the charged body and the pendulum ball in the textbook, it saves operation time, improves experimental efficiency, and improves the convenience of operation. In addition, the electronic balance can directly display the magnitude of the Coulomb force, making the experimental data easy to observe.

[0018] Compared with the prior art, other solutions of the present invention have achieved the following technical effects:

[0019] The disc-shaped structure of the metal sheet and the metal tray can ensure that the radius of curvature is the same everywhere on the boundary, thereby ensuring the symmetry of the charge distribution.

[0020] The outer surfaces of the metal sheet and the metal tray are smoothly arranged to avoid the problem of uneven charge distribution caused by pointed protrusions and improve the uniformity of charge distribution.

[0021] The setting of the lifting platform and the supporting frame improves the convenience of adjusting the height of the metal sheet.

[0022] The airtight box can provide a good airtight environment. At the same time, with the setting of the heater, the air humidity in the airtight box can be reduced, the dry air state inside the airtight box can be maintained for a long time, and the charge leakage can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A schematic diagram of the structure of a Coulomb's law teaching demonstration experimental device in an embodiment of the present invention;

[0025] Among them, 1. Insulating parts; 2. Metal sheets; 3. Electronic balance; 4. Metal tray; 5. Scale lines; 6. Support frame; 7. Lifting platform; 8. Airtight box. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a Coulomb's law teaching demonstration experimental device to solve the problems existing in the prior art. The Coulomb's law experiment can be carried out by using a metal sheet and a metal tray of an electronic balance, the operation is more convenient, and the experimental data are easy to observe.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Please refer to Figure 1 As shown, a Coulomb's law teaching demonstration experimental device is provided, including an insulating member 1, a metal sheet 2 and an electronic balance 3. The metal sheet 2 is located directly above the tray of the electronic balance 3. One end of the insulating member 1 is connected to the end of the metal sheet 2 away from the electronic balance 3. The connection method can be glued. In other embodiments, a snap connection, a threaded connection, etc. can be selected. For example, a snap or a screw that matches the insulating member 1 is glued to the metal sheet 2, and then the insulating member 1 is connected to the snap or the screw; the tray of the electronic balance 3 is a metal tray 4, and the metal tray 4 is grounded; the purpose of the insulating member 1 is to provide a base to help the metal sheet 2 move, so that the operator can hold it and use the insulation to avoid affecting the charge distribution of the metal sheet 2. The insulating member 1 can be round Column rod or square rod, etc.; the experimental principle of this device is: after the metal sheet 2 is powered by the electrostatic charging rod, the metal sheet 2 is close to the grounded metal tray 4 of the electronic balance 3, the grounded metal tray 4 of the electronic balance 3 is induced to be charged, and the electronic balance 3 begins to display the value of the Coulomb force; the distance between the metal sheet 2 and the grounded metal tray 4 of the electronic balance 3 is adjusted by the insulating part 1, and the changing relationship between the electric quantity, distance and Coulomb force can be obtained, so as to complete the teaching demonstration experiment of Coulomb's law, that is, in this device, only the metal sheet 2 needs to be powered, compared with the two power supply of the charged body and the pendulum ball in the textbook, it saves operation time, improves experimental efficiency, and improves the convenience of operation, and the electronic balance 3 can directly display the size of the Coulomb force, so that the experimental data is easy to observe.

[0030] In this embodiment, the electronic balance 3 is an electronic balance 3 with an accuracy of 0.001g.

[0031] In this embodiment, the metal sheet 2 and the metal tray 4 are both disc-shaped structures, which can ensure that the same radius of curvature is present everywhere on the boundary, thereby ensuring the symmetry of the charge distribution.

[0032] In this embodiment, the radius of the metal tray 4 is twice the radius of the metal sheet 2 .

[0033] In this embodiment, the outer surfaces of the metal sheet 2 and the metal tray 4 are smoothly arranged, which can avoid the problem of uneven charge distribution caused by pointed protrusions and improve the uniformity of charge distribution.

[0034] Since the metal sheet 2 cannot be effectively kept stable when the position of the metal sheet 2 is adjusted by holding the insulating part 1, a lifting platform 7 and a support frame 6 are additionally provided in the present application. One end of the support frame 6 is connected to the insulating part 1, and the other end is placed on the lifting platform 7. By adjusting the lifting and lowering of the lifting platform 7, the support frame 6 is driven to move up and down, thereby driving the insulating part 1 and the metal sheet 2 to move closer to or away from the metal tray 4, which not only improves the convenience of adjusting the height of the metal sheet 2, but also improves the positioning stability of the metal sheet 2.

[0035] In this embodiment, the lifting platform 7 is a manual lifting platform. In other embodiments, a pneumatic, hydraulic or electric lifting platform or other structures that can achieve lifting motion can be selected.

[0036] The Coulomb's law teaching demonstration experimental device in this embodiment also includes an airtight box 8. The top cover of the airtight box 8 is detachable. The top cover of the airtight box 8 is provided with a through hole for the insulating member 1 to extend into. The insulating member 1 and the top cover of the airtight box 8 are vertically arranged. The metal sheet 2 and the electronic balance 3 are both located in the airtight box 8. The setting of the airtight box 8 provides a good airtight environment, reducing the air exchange between the inside of the box and the outside. When installing the device, the insulating member 1 can be inserted into the through hole first, and then the metal sheet 2 is connected, and then the top cover of the airtight box 8 can be buckled.

[0037] The insulating part 1 is provided with scale lines 5 by pasting scale paper, printing or engraving, or the insulating part 1 is connected with a ruler, and the top cover position of the airtight box 8 is used as a fixed reference object, and the distance between the metal sheet 2 and the metal tray 4 can be judged by the ruler; in other embodiments, an additional fixed reference object can also be provided for the operator to read the distance data, for example, a cross bar is provided on one side of the path of the up and down movement of the insulating part 1, and the cross bar can be erected on one side of the airtight box 8 through a column, and the closer the cross bar is to the insulating part 1, the more conducive it is to improve the accuracy of the reading.

[0038] The Coulomb's law teaching demonstration experimental device also includes a heater for heating the airtight box 8. In this embodiment, the heater is an infrared electric heater. In other embodiments, other types of heaters can also be used. The heater can reduce the air humidity in the airtight box 8, maintain the dry air state inside the airtight box 8 for a long time, and reduce charge leakage.

[0039] In this embodiment, the airtight box 8 is an acrylic airtight box, that is, the material of the airtight box 8 is acrylic, which improves the observability of the experiment.

[0040] The Coulomb's law teaching demonstration experimental device also includes an electrostatic charging rod for electrifying the metal sheet 2. The electrostatic charging rod is used in conjunction with the metal sheet 2. A groove for preventing the electrostatic charging rod from being used can be set in the airtight box 8, the support table and other positions to facilitate its storage.

[0041] In other embodiments, a slot for accommodating a vernier caliper may be provided at the airtight box 8, the support platform, etc., or the device may be equipped with a vernier caliper to measure the distance of the scale line 5 more accurately.

[0042] During actual use, first open the top cover of the airtight box 8, use an infrared electric heater to preheat the inside of the airtight box 8 for 10-15 minutes, and then place the infrared electric heater in an adjacent position outside the airtight box 8; at this time, power can be supplied to the metal sheet 2, and after power supply is completed, cover the top cover of the airtight box 8, and adjust the position of the metal sheet 2 by adjusting the lifting platform 7 to start the teaching demonstration of Coulomb's law.

[0043] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0044] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0045] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A Coulomb's law teaching demonstration experimental device, characterized in that: The device comprises an insulating member, a metal sheet and an electronic balance. The metal sheet is located directly above a tray of the electronic balance. One end of the insulating member is connected to an end of the metal sheet away from the electronic balance. The tray of the electronic balance is a metal tray which is grounded.

2. The Coulomb's law teaching demonstration experimental device according to claim 1 is characterized in that: The metal sheet and the metal tray are both disc-shaped structures.

3. The Coulomb's law teaching demonstration experimental device according to claim 1 is characterized in that: The metal sheet and the outer surface of the metal tray are arranged smoothly.

4. The Coulomb's law teaching demonstration experimental device according to claim 1 is characterized in that: The Coulomb's law teaching demonstration experimental device also includes a lifting platform and a support frame, one end of the support frame is connected to the insulating member, and the other end is placed on the lifting platform.

5. The Coulomb's law teaching demonstration experimental device according to claim 4 is characterized in that: The lifting platform is a manual lifting platform.

6. The Coulomb's law teaching demonstration experimental device according to claim 1 is characterized in that: The Coulomb's law teaching demonstration experimental device also includes an airtight box, the top cover of the airtight box is detachable, the top cover of the airtight box is provided with a through hole for the insulating member to extend into, the insulating member is vertically arranged to the top cover of the airtight box, and the metal sheet and the electronic antenna are both located in the airtight box.

7. The Coulomb's law teaching demonstration experimental device according to claim 6 is characterized in that: The insulating member is provided with scale lines, or the insulating member is connected with a scale.

8. The Coulomb's law teaching demonstration experimental device according to claim 6 is characterized in that: The Coulomb's law teaching demonstration experimental device also includes a heater for heating the airtight box.

9. The Coulomb's law teaching demonstration experimental device according to claim 6, characterized in that: The airtight box is an acrylic airtight box.

10. The Coulomb's law teaching demonstration experimental device according to claim 1, characterized in that: The Coulomb's law teaching demonstration experimental device also includes an electrostatic charging rod for electrifying the metal sheet.

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