Question

Consider the situation given in figure. The wire AB is slid on the fixed rails with a constant velocity. If the wire AB is replaced by a semicircular wire, the magnitude of the induced current will

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

Answer 1

Answer: (D)

The induced,emf $e=l\left(\vec{V}\times \vec{B}\right)=l\left(vBsin\theta \right)=Bvl$
Induced current, $i=\frac{e}{R}$
If the straight wire is replaced by a semicircular wire, resistance R remains unchanged. Hence, current remains same.