Question

Assertion :A current carrying loop is placed in uniform magnetic field as shown in figure.Torque in the loop in this case is zero. Reason: Magnetic moment vector of the loop is perpendicular to paper inwards.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is D Both Assertion and Reason are incorrect

Torque, $\tau =mB\sin \theta$

Here, $\theta ={90}^o$ so, $\tau \ne 0$

Magnetic moment, $m=IA$

So, the magnetic moment is the direction of area i.e perpendicular to the paper outwards.