Biot-savart law experimental verification device and verification experiment method

Abstract

A kind of Biot-Savart law experimental verification device, one side of base is equipped with DC power supply component, middle part is provided with the installation groove of "day" shape, the other side is equipped with gauss meter, installation groove is composed of upper edge groove, middle groove, lower edge groove, first single wire is arranged in upper edge groove, second single wire is arranged in lower edge groove, installation seat is arranged on the outer side of middle groove two ends of base, installation seat is equipped with experimental board perpendicular to the upper surface of base, experimental board is transparent insulating board, and first coaxial cable is arranged on it, the positive output end of DC power supply component is detachably connected with the left end of inner conductor of first coaxial cable, the right end of inner conductor of first coaxial cable is connected with the right end of first single wire, the left end of first single wire is detachably connected with the outer conductor of left end of first coaxial cable, the outer conductor of right end of first coaxial cable is detachably connected with the right end of second single wire, and the left end of second single wire is detachably connected with the negative pole of DC power supply component.

Description

Technical Field

[0001] This invention belongs to the technical field of electromagnetic experimental teaching instruments, specifically involving a Biot-Savart law experimental verification device and verification experimental method. Background Technology

[0002] The Biot-Savart law, also known as the Biot-Savart law, is one of the important laws taught in university courses such as Electromagnetism, Electrodynamics, and Electromagnetic Field Theory. It was established because French physicists Biot and Savart were dissatisfied with the qualitative descriptions of the magnetic effect of electric current by Oersted and others, and sought to find a universal law governing the action of electric current on magnetic poles. Through two ingeniously designed experiments, using the method of periodic oscillation of a magnetic needle, they discovered the law governing the action of direct current on a magnetic needle. This action is directly proportional to the intensity of the current and inversely proportional to the distance between them, and the direction of the force is perpendicular to the line connecting the magnetic needle to the conductor. French mathematician Laplace used brilliant mathematical analysis to elevate their experimental results to a theoretical level, assuming that the effect of current can be considered as the sum of the individual effects of each current element, expressing this law in differential form, thus deriving the Biot-Savart law. The Biot-Savart law represents the first quantitative study of the magnetic effect of electric current in human history, becoming one of the most important fundamental experimental laws in electromagnetism and marking a milestone in the development of electromagnetism.

[0003] Although the Biot-Savart law is a fundamental law of electromagnetism directly derived from experimental results, the current element vector in the law is a scientific abstraction. In reality, any current must form a loop within a finite space; independent current elements cannot exist. Therefore, the distribution of the magnetic field formed by independent current elements in space cannot be determined by direct experiments. The correctness and scientific validity of the law can only be determined by comparing the magnetic field distribution calculated by the law with experimental measurements. Of course, the Biot-Savart law has long been rigorously tested and is undoubtedly correct. Theoretically, the Biot-Savart law can be used to calculate the magnetic field produced by the current in any segment of a circuit. For example, in electromagnetism courses, there are often problems involving calculating the magnetic induction intensity produced at a specific point in space by the current in a circular arc segment or a finite-length straight segment. However, this is limited to calculation; there has been no corresponding experimental design or verification device. The reason is that it is difficult to construct a "headless" and "tailless" current-carrying "independent" circuit in an experiment, which poses a significant challenge to students' experimental verification of the Biot-Savart law. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a Biot-Savart law experimental verification device and verification experimental method that is simple in structure, easy to operate, and provides intuitive and clear experimental results.

[0005] The technical solution adopted to solve the above technical problems is as follows: A Biot-Savart law experimental verification device. On one side of the insulating base, there is a DC power supply component. In the middle, there is a "day" - shaped installation groove. On the other side, there is a gaussmeter. The installation groove consists of an upper groove, a middle groove, and a lower groove. In the upper groove, there is a first single - strand wire. In the lower groove, there is a second single - strand wire. On the base outside both ends of the middle groove, there are mounting seats. On the mounting seats, there is an experimental board perpendicular to the upper surface of the base. The experimental board is a transparent insulating board with a first coaxial cable. The experimental board is parallel to the middle groove and is directly above the middle groove. The positive output terminal of the DC power supply component is detachably connected to the inner conductor at the left end of the first coaxial cable. The inner conductor at the right end of the first coaxial cable is detachably connected to the right end of the first single - strand wire. The left end of the first single - strand wire is detachably connected to the outer conductor at the left end of the first coaxial cable. The outer conductor at the right end of the first coaxial cable is detachably connected to the right end of the second single - strand wire. The left end of the second single - strand wire is detachably connected to the negative pole of the DC power supply component;

[0006] The experimental board is one of the first experimental board, the second experimental board, and the third experimental board; The transparent insulating boards of the first experimental board, the second experimental board, and the third experimental board have the same size; The first experimental board is a transparent insulating board with a straight - shaped first coaxial cable at the bottom. The length of the first coaxial cable is equal to the length of the middle groove. On the transparent insulating board, there is a magnetic induction intensity measurement point A. The magnetic induction intensity measurement point A is directly above the mid - point of the first coaxial cable. The distance between the magnetic induction intensity measurement point A and the first coaxial cable is times the length of the first coaxial cable; The second experimental board is a transparent insulating board with a semi - circular first coaxial cable and a marked magnetic induction intensity measurement point D. The semi - circular diameter of the semi - circular first coaxial cable is equal to the length of the middle groove; The magnetic induction intensity measurement point D is located at the center of the semi - circular first coaxial cable; The third experimental board is a transparent insulating board with a first coaxial cable whose two sides are oblique straight lines and the middle part is a concave - down circular arc. The straight lines where the two oblique straight - line segments of the first coaxial cable are located are orthogonal. The intersection point of the orthogonality is the center of the concave - down circular arc segment in the middle and is the magnetic induction intensity measurement point C.

[0007] As a preferred technical solution, the transparent insulating board is a plexiglass board.

[0008] As a preferred technical solution, the DC power supply component includes a DC power supply, a variable resistor, an ammeter, and a second coaxial cable; The positive pole of the DC power supply is successively connected in series with an ammeter, a variable resistor, and the inner conductor at one end of the second coaxial cable. The inner conductor at the other end of the second coaxial cable is connected to the inner conductor at the left end of the first coaxial cable, and the negative pole of the DC power supply is connected to the outer conductor at one end of the second coaxial cable. The other end of the outer conductor of the second coaxial cable is connected to the left end of the second single - strand wire.

[0009] This invention also provides a verification experimental method for the Biot-Savart law experimental verification device, comprising the following steps:

[0010] Step 1. Verify the magnetic field strength on the perpendicular bisector of a straight conductor segment under energized conditions.

[0011] Step 1.1. Install the first experimental board on the mounting base, connect the first coaxial cable to the circuit, turn on the circuit, and use a gaussmeter to measure the magnetic induction intensity value at point A on the first experimental board.

[0012] Step 1.2. Using the relevant parameters corresponding to the first coaxial cable on the first experimental board and the magnetic induction intensity measurement point A, calculate the theoretical value of the magnetic induction intensity at the magnetic induction intensity measurement point A using the formula (1) for the magnetic induction intensity generated in space by a long straight conductor obtained from the Biot-Savart law.

[0013]

[0014] In the formula, μ0 is the vacuum permeability, I is the current value through the first coaxial cable, r0 is the distance from the measurement point to the straight conductor, θ1 is the angle between the line connecting the measurement point A to the left end of the first coaxial cable and the center line of the first coaxial cable; θ2 is the angle between the line connecting the measurement point A to the right end of the first coaxial cable and the right extension of the center line of the first coaxial cable.

[0015] Step 1.3. Compare the measurement results of Step 1.1 with the theoretical values ​​of Step 1.2. If they are the same, then the formula (1) is verified to be correct.

[0016] Step 2. Verify the magnetic induction intensity at the center of the semicircular conductor segment under energized conditions.

[0017] Step 2.1. Remove the first experimental board, install the second experimental board on the mounting base, connect the first coaxial cable of the second experimental board to the circuit, turn on the circuit, and use a gaussmeter to measure the magnetic induction intensity value at the magnetic induction intensity measurement point D.

[0018] Step 2.2. Using the relevant parameters corresponding to the first coaxial cable and magnetic induction intensity measurement point D on the second experimental board, calculate the theoretical value B1 of the magnetic induction intensity at the magnetic induction intensity measurement point D on the second experimental board according to the following formula (2) obtained from the Biot-Savart law;

[0019]

[0020] In the formula, I is the current value through the first coaxial cable, and R is the radius of the semicircle of the first coaxial cable.

[0021] Step 2.3. Compare the measurement results of Step 2.1 with the theoretical values ​​of Step 2.2 to verify the correctness of Formula (2);

[0022] Step 3. Verify the magnetic induction intensity at the center of the arc-shaped conductor segment under energized conditions.

[0023] Step 3.1. Remove the second experimental board, install the third experimental board on the mounting base, connect the first coaxial cable of the third experimental board to the circuit, turn on the circuit, and use a gaussmeter to measure the magnetic induction intensity value at the magnetic induction intensity measurement point C.

[0024] Step 3.2. Using the relevant parameters corresponding to the first coaxial cable and magnetic induction intensity measurement point C on the third experimental board, calculate the theoretical value B2 of the magnetic induction intensity at the magnetic induction intensity measurement point C on the third experimental board according to the following formula (3) obtained from the Biot-Savart law;

[0025]

[0026] In the formula, I is the current value through the first coaxial cable, and R is the radius of the concave arc-shaped first coaxial cable;

[0027] Step 3.3. Compare the measurement results of Step 3.1 with the theoretical values ​​of Step 3.2 to verify the correctness of Formula (3).

[0028] The beneficial effects of this invention are as follows:

[0029] This invention cleverly utilizes the vector characteristics of magnetic induction intensity and the structural features of coaxial cables to construct three conductive line segments that are "equivalently independent" relative to the measurement point. This allows for experimental verification of the magnetic induction intensity values ​​at the measurement point for a straight, semi-circular, and arc-shaped line segment under energized conditions, calculated using the Biot-Savart law. Furthermore, this invention is significant for students in establishing a physical picture of the spatial distribution of magnetic fields and gaining a deep understanding of the vector characteristics of magnetic induction intensity. This invention has the advantages of simple structure, low manufacturing cost, and convenient operation, and can be used for both quantitative measurement experiments for students and classroom demonstration experiments. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention.

[0031] Figure 2 yes Figure 1 Top view.

[0032] Figure 3 This is a schematic diagram of the circuit principle of the present invention.

[0033] Figure 4 This is a schematic diagram of the structure of the first experimental plate of the present invention.

[0034] Figure 5 It is a schematic structural diagram of the second experimental board of the present invention.

[0035] Figure 6 It is a schematic structural diagram of the third experimental board of the present invention.

[0036] Wherein: DC power supply 1, base 2, mounting seat 3, experimental board 4, transparent insulating board 41, first coaxial cable 42, gaussmeter 5, ammeter 6, adjustable resistor 7, second coaxial cable 8, mounting groove 9, upper groove 91, middle groove 92, lower groove 93, first single-strand wire 10, second single-strand wire 11. Specific embodiments

[0037] The present invention will be further described in detail below in conjunction with the drawings and embodiments, but the present invention is not limited to the following embodiments.

[0038] In Figure 1 、 2 、3, an experimental verification device for Biot-Savart law in this embodiment is composed of a base 2, a mounting seat 3, an experimental board 4, a transparent insulating board 41, a first coaxial cable 42, a gaussmeter 5, a first single-strand wire 10, a second single-strand wire 11, and a DC power supply component connected.

[0039] On one side of the insulating base 2, a DC power supply component is provided, in the middle part, a "day"-shaped mounting groove 9 is provided, and on the other side, a gaussmeter 5 is provided. The mounting groove 9 is composed of an upper groove 91, a middle groove 92, and a lower groove 93. The first single-strand wire 10 is installed in the upper groove 91, and the second single-strand wire 11 is installed in the lower groove 93. The first single-strand wire 10 and the second single-strand wire 11 are symmetric with respect to the middle groove 92. Mounting seats 3 are installed on the base 2 at both ends outside the middle groove 92. An experimental board 4 perpendicular to the upper surface of the base 2 is installed on the mounting seats 3. The experimental board 4 is a transparent insulating board 41 on which a first coaxial cable 42 is fixedly installed. The experimental board 4 is parallel to the middle groove 92 and is located directly above the middle groove 92. The positive output terminal of the DC power supply component is detachably connected to the inner conductor at the left end of the first coaxial cable 42. The inner conductor at the right end of the first coaxial cable 42 is detachably connected to the right end of the first single-strand wire 10. The left end of the first single-strand wire 10 is detachably connected to the outer conductor at the left end of the first coaxial cable 42. The outer conductor at the right end of the first coaxial cable 42 is detachably connected to the right end of the second single-strand wire 11. The left end of the second single-strand wire 11 is detachably connected to the negative pole of the DC power supply component; after being powered on, the current direction in the first single-strand wire 10 is counterclockwise, and the current direction in the second single-strand wire 11 is clockwise. The current intensities in the first single-strand wire 10 and the second single-strand wire 11 are equal. The current magnitudes in the inner conductor and the outer conductor of the first coaxial cable 42 are equal and the directions are the same. The total current intensity in the first coaxial cable 42 is twice the current intensity in the first single-strand wire 10 or the second single-strand wire 11.

[0040] The DC power supply assembly of this embodiment includes a DC power supply 1, an adjustable resistor 7, an ammeter 6, and a second coaxial cable 8. The positive terminal of the DC power supply 1 is connected in series with the ammeter 6, the adjustable resistor 7, and the inner conductor of one end of the second coaxial cable 8. The inner conductor of the other end of the second coaxial cable 8 is connected to the inner conductor of the left end of the first coaxial cable 42. The negative terminal of the DC power supply 1 is connected to the outer conductor of one end of the second coaxial cable 8. The outer conductor of the other end of the second coaxial cable 8 is connected to the left end of the second single-strand wire 11.

[0041] In this embodiment, the experimental board 4 is one of the first, second, and third experimental boards. The transparent insulating plates 41 of the first, second, and third experimental boards are of the same size. The first experimental board has a straight first coaxial cable 42 fixedly installed at the bottom of the transparent insulating plate 41. The length of the first coaxial cable 42 is equal to the length of the intermediate groove 92. When installing the first experimental board, the first coaxial cable 42 is embedded in the intermediate groove 92. A magnetic induction intensity measurement point A is marked on the transparent insulating plate 41. The magnetic induction intensity measurement point A is located directly above the midpoint of the first coaxial cable 42, and the distance between the magnetic induction intensity measurement point A and the first coaxial cable 42 is equal to the length of the first coaxial cable 42. times, such as Figure 4 In this embodiment, the length of the first coaxial cable 42 is 30cm, and the distance between the measuring point A and the first coaxial cable 42 is 8.6cm. The second experimental board is a transparent insulating board 41 on which a semi-circular first coaxial cable 42 and a marked magnetic induction intensity measuring point D are embedded. The semi-circular diameter of the first coaxial cable 42 is equal to the length of the central groove 92, which is 30cm. The magnetic induction intensity measuring point D is located at the center of the semi-circular first coaxial cable 42. Figure 5 The third experimental board is a transparent insulating board 41 on which a first coaxial cable 42 is inlaid. The two oblique straight segments of the first coaxial cable 42 are orthogonal, and the intersection point is the center of the circle opposite the concave arc segment in the middle, which is also the magnetic induction intensity measurement point C. The radius of the concave arc segment in the middle of the first coaxial cable 42 is 10cm. Figure 6 .

[0042] In this embodiment, the transparent insulating plate 41 of the experimental plate 4 is an plexiglass plate.

[0043] Based on the vector characteristics of magnetic induction intensity and the symmetry between the first single-strand wire 10 and the second single-strand wire 11 with the intermediate slot 92, and the fact that the current in the circuit formed by the inner conductor of the first coaxial cable 42 and the first single-strand wire 10 is equal in magnitude and opposite in direction to the current in the circuit formed by the outer conductor of the first coaxial cable 42 and the second single-strand wire 11, this invention ensures that after the circuit is energized, the magnetic induction intensities generated by the currents in the first single-strand wire 10 and the second single-strand wire 11 at the magnetic induction intensity measurement points on the three experimental boards are equal in magnitude and opposite in direction, thus completely canceling each other out. That is, the direction and magnitude of the magnetic induction intensity at the magnetic induction intensity measurement point are only related to the current intensity in the respective first coaxial cable 42, the shape and length of the coaxial cable, and the position of the measurement point. In other words, relative to the magnetic induction intensity measurement points on the three experimental boards, the first coaxial cable 42 is an equivalent "independent conductive segment". This allows for the comparison and verification of the measured and calculated values ​​of the magnetic induction intensity generated by independent straight, semi-circular, and arc-shaped conductive segments.

[0044] The verification experimental method of the Biot-Savart law experimental verification device in this embodiment includes the following steps:

[0045] Step 1. Verify the magnetic field strength on the perpendicular bisector of a straight conductor segment under energized conditions.

[0046] Step 1.1. Install the first experimental board on the mounting base 3, connect the first coaxial cable 42 to the circuit, turn on the circuit, the DC power supply 1 outputs a current of 15A, then the current through the first coaxial cable 42 is 30A, and use a gaussmeter 5 to measure the magnetic induction intensity at point A on the first experimental board, the value is 0.60GS.

[0047] Step 1.2. Using the relevant parameters corresponding to the first coaxial cable 42 on the first experimental board and the magnetic induction intensity measurement point A, the formula (1) for the magnetic induction intensity generated in space by a long straight conductor obtained from the Biot-Savart law is used.

[0048]

[0049] Calculate the theoretical value of the magnetic induction intensity at measurement point A. In the formula, μ0 is the permeability of free space, I is the current value through the first coaxial cable 42, I = 30A, r0 is the distance from the measurement point to the straight conductor, r0 = 8.6cm, θ1 is the angle between the line connecting the measurement point A and the left end of the first coaxial cable 42 and the center line of the first coaxial cable 42, θ1 = 30°; θ2 is the angle between the line connecting the measurement point A and the right end of the first coaxial cable 42 and the right extension of the center line of the first coaxial cable 42, θ2 = 150°.

[0050] The calculated magnetic flux density at measurement point A is 0.60 GS.

[0051] Step 1.3. Compare the measurement results of Step 1.1 with the theoretical values ​​of Step 1.2. If they are the same, then the formula (1) is verified to be correct.

[0052] Step 2. Verify the magnetic induction intensity at the center of the semicircular conductor segment under energized conditions.

[0053] Step 2.1. Remove the first experimental board, install the second experimental board on the mounting base 3, connect the first coaxial cable 42 of the second experimental board to the circuit, turn on the circuit, the current through the first coaxial cable 42 is 30A, and use a gaussmeter 5 to measure the magnetic induction intensity at the measurement point D, the value of which is 0.63GS.

[0054] Step 2.2. Using the relevant parameters corresponding to the first coaxial cable 42 and the magnetic induction intensity measurement point D on the second experimental board, calculate the theoretical value B1 of the magnetic induction intensity at the magnetic induction intensity measurement point D on the second experimental board according to the following formula (2) obtained from the Biot-Savart law;

[0055]

[0056] In the formula, I is the current value through the first coaxial cable 42, I = 30A, R is the radius of the arc of the semi-circular first coaxial cable 42, R = 15cm, and B = 0.63GS;

[0057] Step 2.3. Compare the measurement results of Step 2.1 with the theoretical values ​​of Step 2.2. If they are the same, then the formula (2) is verified to be correct.

[0058] Step 3. Verify the magnetic induction intensity at the center of the arc-shaped conductor segment under energized conditions.

[0059] Step 3.1. Remove the second experimental board, install the third experimental board on the mounting base 3, connect the first coaxial cable 42 of the third experimental board to the circuit, turn on the circuit, the current through the first coaxial cable 42 is 30A, and use a gaussmeter 5 to measure the magnetic induction intensity at the measurement point C, the value of which is 0.47GS.

[0060] Step 3.2. Using the relevant parameters corresponding to the first coaxial cable 42 and the magnetic induction intensity measurement point C on the third experimental board, calculate the theoretical value B2 of the magnetic induction intensity at the magnetic induction intensity measurement point C on the third experimental board according to the following formula (3) obtained from the Biot-Savart law;

[0061]

[0062] In the formula, I is the current value through the first coaxial cable 42, I = 30A, R1 is the radius of the concave arc segment in the middle, R1 = 10cm, and B2 = 0.47GS;

[0063] Step 3.3. Compare the measurement results of step 3.1 with the theoretical values ​​of step 3.2. If they are the same, then the formula (3) is verified to be correct.

Claims

1. An experimental verification apparatus for Biot-Savart's law, characterized in that: On one side of the base of the insulator, a DC power supply component is provided. In the middle, an "O" - shaped installation groove is provided. On the other side, a gauss meter is provided. The installation groove consists of an upper groove, a middle groove, and a lower groove. In the upper groove, a first single - strand wire is provided. In the lower groove, a second single - strand wire is provided. On the base outside both ends of the middle groove, mounting seats are provided. On the mounting seats, an experimental board perpendicular to the upper surface of the base is provided. The experimental board is a transparent insulating board on which a first coaxial cable is provided. The experimental board is parallel to the middle groove and is located directly above the middle groove. The positive output terminal of the DC power supply component is detachably connected to the inner conductor of the left end of the first coaxial cable. The inner conductor of the right end of the first coaxial cable is detachably connected to the right end of the first single - strand wire. The left end of the first single - strand wire is detachably connected to the outer conductor of the left end of the first coaxial cable. The outer conductor of the right end of the first coaxial cable is detachably connected to the right end of the second single - strand wire. The left end of the second single - strand wire is detachably connected to the negative pole of the DC power supply component; The experimental board is one of the first, second, and third experimental boards; the transparent insulating plates of the first, second, and third experimental boards are of the same size; the first experimental board has a straight first coaxial cable at the bottom of the transparent insulating plate, the length of the first coaxial cable being equal to the length of the central groove, and a magnetic induction intensity measurement point A is marked on the transparent insulating plate, located directly above the midpoint of the first coaxial cable, with the distance between the magnetic induction intensity measurement point A and the first coaxial cable being the length of the first coaxial cable. The second experimental board is a transparent insulating board with a semi-circular first coaxial cable and a magnetic induction intensity measurement point D marked on it. The semi-circular diameter of the first coaxial cable is equal to the length of the middle groove. The magnetic induction intensity measurement point D is located at the center of the semi-circular first coaxial cable. The third experimental board is a transparent insulating board with a first coaxial cable on both sides that are oblique straight lines and in the middle that is concave arc. The two oblique straight line segments of the first coaxial cable are orthogonal, and the intersection point is the center of the concave arc segment in the middle, which is also the magnetic induction intensity measurement point C.

2. The experimental verification apparatus for Biot-Savart's law according to claim 1, characterized in that: The transparent insulating board is a plexiglass board.

3. The experimental verification apparatus for Biot-Savart's law according to claim 1, characterized in that: The DC power supply component includes a DC power supply, a variable resistor, an ammeter, and a second coaxial cable; the positive pole of the DC power supply is sequentially connected in series with an ammeter, a variable resistor, and the inner conductor of one end of the second coaxial cable. The inner conductor of the other end of the second coaxial cable is connected to the inner conductor of the left end of the first coaxial cable. The negative pole of the DC power supply is connected to the outer conductor of one end of the second coaxial cable. The other end of the outer conductor of the second coaxial cable is connected to the left end of the second single - strand wire.

4. The verification experimental method of the Biot-Savart law experimental verification device according to claim 1, characterized in that, It includes the following steps: Step 1. Verify the magnetic induction intensity on the perpendicular bisector of a straight - wire segment in the energized state Step 1.

1. Install the first experimental board on the mounting seat, connect the first coaxial cable to the circuit, turn on the circuit, and use the gauss meter to measure the magnetic induction intensity value at the magnetic induction intensity measurement point A on the first experimental board; Step 1.

2. Based on the relevant parameters corresponding to the first coaxial cable and the magnetic induction intensity measurement point A on the first experimental board, use the magnetic induction intensity formula (1) generated by a long - straight wire in space obtained from the Biot - Savart law to calculate the theoretical value of the magnetic induction intensity at the magnetic induction intensity measurement point A, In the formula, μ0 is the vacuum permeability, I is the current value passing through the first coaxial cable, r0 is the distance from the measurement point to the straight wire, θ1 is the angle between the connection line between the measurement point A and the left end of the first coaxial cable and the center line of the first coaxial cable; θ2 is the angle between the connection line between the measurement point A and the right end of the first coaxial cable and the right - extended center line of the first coaxial cable; Step 1.

3. Compare the measurement result in Step 1.1 with the theoretical value in Step 1.

2. If they are the same, it is verified that formula (1) is correct; Step 2. Verify the magnetic induction intensity at the center of the circle corresponding to a semicircular wire segment in the energized state Step 2.

1. Remove the first experimental board, install the second experimental board on the mounting seat, connect the first coaxial cable of the second experimental board to the circuit, turn on the circuit, and use the gauss meter to measure the magnetic induction intensity value at the magnetic induction intensity measurement point D; Step 2.

2. Using the relevant parameters corresponding to the first coaxial cable and magnetic induction intensity measurement point D on the second experimental board, calculate the theoretical value B1 of the magnetic induction intensity at the magnetic induction intensity measurement point D on the second experimental board according to the following formula (2) obtained from the Biot-Savart law; In the formula, I is the current value through the first coaxial cable, and R is the radius of the semicircle of the first coaxial cable. Step 2.

3. Compare the measurement results of Step 2.1 with the theoretical values ​​of Step 2.2 to verify the correctness of Formula (2); Step 3. Verify the magnetic induction intensity at the center of the arc-shaped conductor segment under energized conditions. Step 3.

1. Remove the second experimental board, install the third experimental board on the mounting base, connect the first coaxial cable of the third experimental board to the circuit, turn on the circuit, and use a gaussmeter to measure the magnetic induction intensity value at the magnetic induction intensity measurement point C. Step 3.

2. Using the relevant parameters corresponding to the first coaxial cable and magnetic induction intensity measurement point C on the third experimental board, calculate the theoretical value B2 of the magnetic induction intensity at the magnetic induction intensity measurement point C on the third experimental board according to the following formula (3) obtained from the Biot-Savart law; In the formula, I is the current value through the first coaxial cable, and R is the radius of the concave arc-shaped first coaxial cable; Step 3.

3. Compare the measurement results of Step 3.1 with the theoretical values ​​of Step 3.2 to verify the correctness of Formula (3).

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