What are the characteristics of the magnetic field of a Helmholtz coil 20

I just wrote this lab report today, so let me do it.

If the opposite current is passed, the magnetic field in the middle of the Helmholtz coil will be equal to zero in front of the magnetic induction. The magnetic induction intensity at both ends gradually decreases outward, but the magnetic induction intensity is greater than that of the previous series connection.

Helmholtz Experiment Measuring Magnetic Field Principle: A Helmholtz coil is made up of two identical coils placed coaxially, with a central spacing equal to the radius of the coil. When the two coils are connected with the same current, the superposition of the magnetic field is enhanced, and an approximately uniform magnetic field is formed in a certain area. When a reverse current is applied, the superposition weakens the magnetic field to the point where an area of zero magnetic field appears.

A Helmholtz coil is a pair of coaxial circular coils that are parallel and connected to each other, and the current in the two coils is in the same direction and of the same size. The distance d between the coils is exactly equal to the radius r of the circular coil, and this circular current-carrying coil is called a helmhohz coil. This coil is characterized by its ability to generate a wide and uniform magnetic field near the midpoint of its common axis.

The theoretical root of the theoretical transformation of the magnetic field generated by a Helmholtz coil is the Biot-Savar law, which is applicable to the calculation of the magnetic field generated by a stable electric current. This current is a charge that flows continuously through a wire, the amount of current does not change over time, and the charge does not accumulate or disappear at any location.

When a constant current is applied to the Hall element, it induces the Hall voltage in the magnetic field, and the Hall voltage is proportional to the magnetic induction intensity at the Hall element, so the magnetic field can be measured with the Hall element. In this experiment, the electronic screen displays the value of the amplified Hall voltage, which is consistent with the change law of the magnetic field where it is located.

A Helmholtz coil is an electromagnet that consists of two parallel coils in the same direction.

When an electric current of equal size, reversed is passed through these two coils, a uniform magnetic field is created between them. The characteristics of the three-dimensional vector distribution of the magnetic field:

1.Uniformity:The magnetic field generated by the Helmholtz coil is very uniform and does not change with position in space.

2.Symmetry:Since the two coils are perfectly symmetrical, the resulting magnetic field is also highly symmetrical.

3.Directionality:The direction of the magnetic field generated by the Helmholtz line circle is perpendicular to its axis, showing the strongest value near the axis, and gradually decreasing along the axis.

4.Controllability:By adjusting parameters such as current and number of conductors, the magnitude and distribution of the magnetic field generated by the Helmholtz coil can be effectively controlled.

5.Wide range of applications:Due to its good uniformity and controllability, it has been widely used in scientific experiments, precision measurement, material testing and other fields.

If there is a pair of current-carrying coils parallel to each other and coaxial, and the current is passed in the same direction, when the coil spacing is equal to the radius of the coil, the total magnetic field of the two current-carrying coils is uniform in a large range near the midpoint of the shaft. Therefore, it has great practical value in production and Coriolis research, and is also often used in the measurement standard of weak magnetic field.

Summary. The magnetic field generated by the Helmholtz coil is uniform, vertical, size-controllable and symmetrical along the axis.

The magnetic field generated by the Helmholtz coil is uniform, vertical, size-controllable and symmetrical along the axis.

1. Uniform magnetic field strength: In the central area of the Helmholtz coil, the magnetic field strength is almost uniform. This is because the distance between the two coils is equal to their radius, so the magnetic field they produce can be approximated as coming from two straight wires of infinite length.

2.The direction of the magnetic field is perpendicular to the axis of the coil: The direction of the magnetic field of the Helmholtz coil is split directly from the axis, which means that the direction of the magnetic field is the same at all points in the region.

3.The magnitude of the magnetic field is affected by the current and the radius of the coil: The magnitude of the magnetic field of a Helmholtz coil is related to the current and the radius of the coil.

When the current increases or the radius of the coil decreases, the magnetic field strength also increases. 4.The magnetic field is axially symmetrical:

The magnetic field of a Helmholtz coil is axially symmetrical, which means that the magnitude of the magnetic field is the same at each point along the axis within that region.

The direction of the magnetic field is perpendicular to the plane of the coil, and the direction is by the right-hand spiral rule.

Judgment. The Hermholtz coil is composed of two radius, the number of turns, the same current from the coil from the radius, and the same direction of the running current, the basic condition is the above several requirements, the magnetic field is characterized by the internal production of a higher uniformity of the magnetic field, the uniformity of the general long solenoid is better than that of the Helmholtz coil, but the compensation coil can be added to both to obtain a high uniformity.

There is the formula b=(miu0)i r 2 ((r 2+x 2).

x is the distance to the axis of the pitch.

The helmholtz coil is two sets of tightly wound coils with the same current direction, and the forest is placed in parallel.

Summary. Hello, "Let's start by looking at the magnetic field distribution of an energized circle. According to Biot-Savar's law, it is obtained by integral operation; On the axis that passes through the center of the circle and is perpendicular to the plane of the coil, at the distance x from the center of the circle, the magnitude of the magnetic field is b=u*r2*i 2[r2+x2][3 2], where i is the magnitude of the current, r is the radius of the circle, and u is a constant.

A Helmholtz coil is two coaxial circular coils that are parallel and connected to each other, and his magnetic field distribution is the superposition of the magnetic fields of the two energized circles. The radius and the distance between the two circles are different, and the result of the superposition is also different. It is gradually weakened outside the two coils, but between the two coils it may be the weakest in the middle or the strongest in the middle, and the radial magnetic field of the Helmholtz coil is distributed.

Hello, "Let's start by looking at the magnetic field distribution of an energized circle. According to Biot-Savar's law, it is obtained by integral operation; On the axis that passes through the center of the circle and is perpendicular to the plane of the coil, at the distance x from the center of the circle, the magnitude of the magnetic field is b=u*r2*i 2[r2+x2][3 2], where i is the magnitude of the current, r is the radius of the circle, and u is a constant. A Helmholtz coil is two coaxial circular coils that are parallel and connected to each other, and his magnetic field distribution is the superposition of the magnetic fields of the two energized circles.

The radius and the distance between the two circles are different, and the result of the superposition is also different. Outside the two coils, Kai is gradually weakened, but between the two staring coils may be the weakest in the middle, or the strongest in the middle, hello, the distribution of the radial magnetic field of the Helm line section without the Holtz coil is as follows:According to Biot-Savar's law, it is obtained by integral operation; On the axis that passes through the center of the circle and is perpendicular to the plane of the coil, at the distance x from the center of the circle, the magnitude of the magnetic field is b=u*r2*i 2[r2+x2][3 2], where i is the magnitude of the current, r is the radius of the circle, and u is a constant.

The Namholtz coil is two coaxial coils that are parallel and connected to each other, and its magnetic field distribution is the superposition of the magnetic fields of the two energized circles. The radius and the distance between the two circles are different, and the result of the superposition is also different. It weakens gradually outside the two coils, but between the two coils it can be the weakest in the middle or the strongest in the middle

What is the magnetic field at 1% of the center of the Helmholtz coil?

The Helmholtz coil is an electromagnet consisting of two coaxial toroidal coils, which generate a stable magnetic field in the center when the current through the two coils is equal and reversed. At this position, the magnetic fields produced by the two coils are opposite in the direction and equal in magnitude, resulting in a net magnetic field of zero. If we shift the position a little bit so that the object is 1% away from the center, then the magnitude of the magnetic field generated by the two coils will be slightly different due to the offset of position, resulting in a net magnetic field that is not zero.

Specifically, the magnitude of the magnetic field at 1% of the center will be about the difference between the magnetic fields generated by the two coils, i.e., b = 2 0Ni(R+D 200) (5 5R) where 0 is the vacuum permeability, n is the number of turns of each coil, i is the current through each coil, r is the radius of each coil, and d is the distance between the two coils. It is important to note that this formula assumes that the Helmholtz coil is ideal, i.e. the magnetic field inside the coil is uniform and there is no magnetic field disturbance between the two coils.

In practice, these assumptions may not be true, so corrections are required for actual measurements.

Two coils of exactly the same radius and number of turns, arranged coaxially so that the spacing is equal to the radius, this combination of coils is called a Helmholtz coil. It can be used to generate extremely weak magnetic fields up to hundreds of gs; The coil has a large uniform area, open use space and easy operation. It can realize one-dimensional, two-dimensional and three-dimensional combined magnetic fields, and can provide AC and DC magnetic fields, and the current has a good linear relationship with the magnetic field.

It is suitable for various research institutes, universities and enterprises to do material magnetic or testing experiments, and is used in various disciplines such as materials, electronics, biology, medicine, aerospace, chemistry, applied physics, etc., and its main uses: to generate standard magnetic fields; Cancellation and compensation of the earth's magnetic field, simulation of the geomagnetic environment, determination of the effect of magnetic shielding, electromagnetic interference simulation experiments, calibration of Hall probes and various magnetometers, research of biomagnetic fields and research on the magnetic properties of substances.

In terms of the development and design of the magnetic field generation of Helmholtz coils: round, square, and octagonal Helmholtz coils, and with the help of finite element design tools, a compensating octagonal Helmholtz coil was developed, which increased the uniform area of the coil by a factor of eight.

When the user chooses the Helmholtz coil, please provide the magnetic field strength, uniform area range and uniformity requirements according to the experimental needs, and the factory provides users with a detailed design method and the selection of the supporting power supply in the shortest possible time.

Areas of application for Helmholtz coils.

Cancellation and compensation of the Earth's magnetic field.

Simulation of the geomagnetic environment.

Determination of magnetic shielding effect.

Electromagnetic interference simulation experiments.

A standard magnetic field is generated.

The study of the amount of biomagnetic field is the study of the magnetic properties of a substance.

A standard magnetic field is generated.

Helmholtz coils are classified using them.

Use with a fluxmeter to measure the magnetic flux of materials;

With permanent magnet quality measuring instrument or magnetic declination measuring instrument, it can further judge the quality of materials and screen incoming materials;

Water-cooled Helmholtz coils can be made according to requirements: the magnetic field value can be in the order of thousands of gauss, to meet customer needs;

One-dimensional, two-dimensional, and three-dimensional square Helmholtz coils can be customized, which are generally used to generate magnetic fields with a relatively large volume and high uniformity in the specified uniform area, and a magnetic field value of several gs to tens of gs.