Complete question:
A small circular coil of 5 turns of wire lies in a uniform magnetic field of 0.8 T, so that the normal to the plane of the coil makes an angle of 100◦ with the direction of B~ . The radius of the coil is 4 cm, and it carries a current of 1 A.
What is magnitude of the magnetic moment of the coil? Answer in units of A · m2.
Answer:
The magnetic moment of the coil is 0.0252 A.m²
Explanation:
Given;
radius of the coil, r = 4 cm = 0.04 m
number of turns of the coil, N = 5 turns
magnetic field strength B = 0.8 T
current in the coil, I = 1 A
Area of the coil, A = πr² = π(0.04)² = 0.00503 m²
magnetic moment of the coil, μ = NIA
where;
N is the number of turns
I is the current in the coil
A is the area of the coil
magnetic moment of the coil, μ = 5 x 1 x 0.00503 = 0.0252 A.m²
Therefore, the magnetic moment of the coil is 0.0252 A.m²
