Question

Consider the situation shown in figure. The wire $\text{AB}$ of zero resistance is allowed to slide on the horizontal fixed rails with a constant velocity. If the wire $\text{AB}$ is replaced by a semicircular wire, the magnitude of the induced current will

• A. Increase
• B. Remain the same
• C. Decrease
• D. Increase or decrease depending on whether the semicircle bulges towards the resistance or away from it.

Answer 1

The correct option is B Remain the same

$\text{CASE-I}$ Semi circular wire:


$\text{CASE-II}$ Straight wire:


In both the cases induced EMF is given by Faraday’s law.
$e=Bvdl$

Here , the effective length is same in both the cases.

Therefore , induced current will remain same in both the cases.

Hence, option (b) is the correct answer.