Question

Resistance per unit length of wire frame ABCDA is $\frac{R}{2l}$. The wire frame is moving with constant velocity $V_0$ on two parallel conducting and smooth horizontal rails in uniform magnetic field B perpendicular to plane of rails as shown in figure.

Select correct option

• A. Current in resistor R is $\frac{2BV_0l}{5R}$
• B. Current in side AB is $\frac{4BV_0l}{5R}$
• C. Current in side CD is $\frac{4BV_0l}{5R}$
• D. Current in side ST is $\frac{2BV_0l}{5R}$

Answer 1

Answer: (A)

Current in resistor R is $\frac{2BV_0l}{5R}

Answer 2

The solution assumes that the total effective resistance of the loop is $\frac{5R}{3}$. Given this assumption, the current in the resistor R is $\frac{2BV_0l}{5R}$. The current division between the resistor R and the segment PT is calculated correctly. However, the calculation of the total resistance of the loop based on the given resistance per unit length leads to a different result, indicating a potential inconsistency in the problem statement.