How to measure magnetic field of a magnet

[Cspeed]

I have a cylindrical neodymium magnet. I know that the magnetic field varies with distance, but how would I determine the magnetic field B at a certain point, through experimentation? I know how to find the force between two magnets at different distances by balancing out with gravity, but I'm stuck as far as measuring fields. Is there an equation which can relate fields and forces for magnets?

 

[f95toli]

If you want an accurate value you will need to measure the field using e.g. a Hall probe.
Instruments used to measure absolute magnetic field are often called Gaussmeters.
They are however quite expensive.

(a more general name for this type of instruments is magnetometer, although that name can also refer to instruments that measure changes in the magnetic field or relative fields)

 

[Cspeed]

Then I guess there's no way to do it economically/creatively? What if MacGuyver only had some duct tape, a paper clip, and a magnet and needed to find out the B?

 

[prince7]

i know that this replay is too late but i have a solution for this
u can build ur own gauss meter with very law cost
if u want to know visit this website
http://www.coolmagnetman.com/magmeter.htm

 

[sardar]

There are several ways to measure the magnetic field of a magnet experimentally. One method is to use a magnetometer, which is a device that can detect and measure magnetic fields. Another method is to use a Hall effect sensor, which measures the voltage produced by a magnetic field. Both of these methods require specialized equipment and are typically used in laboratory settings.

If you do not have access to this equipment, you can still measure the magnetic field of your cylindrical neodymium magnet using a simple experiment. One way is to use a compass to map out the magnetic field lines around the magnet. Place the compass near the magnet and observe the direction of the needle. Move the compass around the magnet and mark the direction of the needle at different points. By connecting these marks, you can create a visual representation of the magnetic field lines.

To determine the strength of the magnetic field at a certain point, you can use the equation B = μ0I/2πr, where B is the magnetic field strength, μ0 is the permeability of free space, I is the current in the magnet (which is zero for a permanent magnet), and r is the distance from the magnet. This equation relates the magnetic field strength to the distance from the magnet and the strength of the magnet.

Another way to measure the magnetic field is to use the force between two magnets. As you mentioned, you can balance out the force between two magnets with gravity to determine the strength of the magnetic field. The equation F = μ0m1m2/4πr2 can be used, where F is the force between the two magnets, μ0 is the permeability of free space, m1 and m2 are the magnetic moments of the two magnets, and r is the distance between them.

Overall, measuring the magnetic field of a magnet can be done through a combination of experimental techniques and mathematical equations. I would recommend using a combination of methods to ensure accuracy in your measurements.