Question

A circular current loop of magnetic moment M is in an arbitrary orientation in an external uniform magnetic field $\overrightarrow{B}$ . The work done to rotate the loop by 30? about an axis perpendicular to its plane is

• A. $\frac{MB}{2}$
• B. MB
• C. Zero
• D. $\sqrt{3} \frac{MB}{2}$

Answer 1

Answer: (C)

Zero

Answer 2

Even though the coil is rotated, about an axis perpendicular to its plane, the potential energy does not change. Hence, work done is zero.