A circular coil having 200 turns, 2.5 10-4 m2 area and carrying 100 current is placed in a uniform magnetic field of 1 T. Initially the magnetic dipole moment ( M) was directed along B. Amount of work, required to rotate the coil through 90 from its initial orientation such that M becomes perpendicular to B, is J.
Answer
5
Solution
W = Uf - Ui = (-MB 90 ) - (-MB 0 ) = MB
M = NIA
W = 200 100 10-6 2.5 10-4 1
= 5 10-6 J = 5
Answer: 5