Question

A circular coil with 200 turns has a radius of 2.0 cm. (a) What current through the coil results in a magnetic dipole moment of 3.0 Am2 ? (b) What is the maximum torque that the coil will experience in a uniform field of strength ? (c) If the angle between µ and B is 45°, what is the magnitude of the torque on the coil? (d) What is the magnetic potential energy of coil for this orientation?

Answer 1

given :

N = 200

r = 2 cm = 0.02 m

a) = magnetic dipole moment = .

also, = current * area * number of turns = i * area * N

[answer]

b) B = magnetic field

Torque of a magnetic dipole in uniform magnetic field is given by

[theta = angle between B and magneitc moment or area vector ]

therefore, maximum torque experienced when theta equals 90 degree,

[answer]

c) if theta = 45 degree, then

[answer]

d) Magnetic potential energy is given by

Magnetic potential energy for this orientation is [answer]