A circular coil of 20 turns and area carries a current of

PHYSICS · Multi-part · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

A circular coil of 20 turns and area

10\,\text{cm}^2

carries a current of

2.0\,\text{A}

. The coil is free to rotate in the horizontal component of the Earth’s magnetic field,

B_h = 3.0\times10^{-5}\,\text{T}

. (i) Determine the work required to turn the coil from a position in which its plane is perpendicular to

\mathbf{B}_h

to a position in which its plane is parallel to

\mathbf{B}_h

. (ii) Comment on the sign of the work obtained and state what it implies about the energy exchange between the coil and the magnetic field.