Question

Assertion :Electric field produced by a variable magnetic field can't exert a force on a charged particle. Reason: This electric field is non-conservative in nature.

• 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. Assertion is incorrect but Reason is correct

Answer 1

The correct option is D Assertion is incorrect but Reason is correct

Let a time varying magnetic field exists inside a solenoid and a charged particle $q$ is placed at a distance $r$ from its center.

Electric field induced due to time varying magnetic field forms a closed loop.

$\therefore$ $\overrightarrow{E}\left(r\right)=\frac{r}{2}\frac{dB}{dt}$ $\hat{\theta }$

Now the force exerted by $E$ on charged particle $\overrightarrow{F}=q\overrightarrow{E}$

Note: Electric field is conservative if $\oint \overrightarrow{E}\left(r\right).\overrightarrow{dl}=0$

But the induced electric field is always in the same direction as that of $\overrightarrow{dl}$ i.e $\overrightarrow{E}\left(r\right)$ $\parallel$ $\overrightarrow{dl}$

$⟹$ $\oint \overrightarrow{E}\left(r\right).\overrightarrow{dl}\ne 0$

Hence the induced electric field is non-conservative.

Thus Assertion is false whereas the Reason statement is true.