Question

A current loop of sides 10 cm and 5 cm carrying a current I of 12 A is placed in different orientations in magnetic field B as shown in the figures below:

If there is a uniform magnetic field of 0.3 T in the positive z direction, in which orientations the loop would be in

(i) stable equilibrium and

(ii) unstable equilibrium?

• A. (a) and (b), respectively
• B. (a) and (c), respectively
• C. (b) and (d), respectively
• D. (b) and (c), respectively

Answer 1

The correct option is C

(b) and (d), respectively

Stable equilibrium $\overrightarrow{M}||\overrightarrow{B}$

Unstable equilibrium $\overrightarrow{M}||(-\overrightarrow{B})$