Question

A wire is bent to form a semicircle of radius a. The wire rotates about its one end with angular velocity w. Axis of rotation being perpendicular to the plane of the semicircle. In the space, a uniform magnetic field of induction B exists along the axis of rotation as shown in figure. Then–

• A. Potential difference between P and Q is equal to 2B wa²
• B. Potential difference between P and Q is equal to 2p²Bwa²
• C. P is at higher than Q
• D. None of these

Answer 1

Answer: (A)

Potential difference between P and Q is equal to 2B wa²

Answer 2

e = $\frac{1}{2}$Bwl² = $\frac{1}{2}$ Bw(2a)² = 2Bwa²