question_answer

             A thin semicircular conducting ring (PQR) of radius 'r' is falling with its plane vertical in a horizontal magnetic field B, as shown in figure. The potential difference developed across thering when its speed is v, is:  

A) Zero           

B) \[Bv\pi {{r}^{2}}/2\] and P is at higher potential   

C) \[\pi rBv\] and R is at higher potential

D) 2rBv and R is at higher potential