Question

A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure.

The potential difference developed across the ring when its speed is v, is

(a) zero

(b) Bvπr²/2 and P is at higher potential

(c) πrBv and R is at higher potential

(d) 2rBv and R is at higher potential

Answer 1

Correct option  (d) 2rBv and R is at higher potential

Explanation:

Motional emf induced in the semicircular ring PQR is equivalent to the motional emf induced in the imaginary conductor PR.

Therefore, potential difference developed across the ring is 2rBv with R is at higher potential.

Comments

Why R is at higher potential?