A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction B. At the position MNQ, the speed of the ring is V and the potential difference developed across the ring is [IIT JEE 1996]

• A.            Zero
• B.            \[B\nu \pi {{R}^{2}}/2\] and M is at higher potential
• C.            \[\pi RBV\]and Q is at higher potential
• D.            2RBV and Q is at higher potential