Question

Assertion :The net magnetic force on a current loop in a uniform magnetic field is zero but torque may or may not be zero. Reason: Torque on a current carrying coil in a magnetic field is given by $\overline{\tau }=nI\left(\overline{A}X\overline{B}\right).$

• 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 B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Since the net torque acting on a current carrying coil is given by:

$\tau =nI(\overrightarrow{A}\times \overrightarrow{B})$

where, $\overrightarrow{A}$ is the area of cross-section through which the magnetic field $\overrightarrow{B}$ passes.

The net force acting on the coil might be zero but it can produce a torque on the coil if it acts in the opposite direction.

Here, assertion and reason both are correct but reason is not the correct explanation of assertion.