a semicircle wire of radius `R` is rotated with constant angular velocity about an axis passing through one end and perpendicular to the plane of wire. There is a uniform magnetic field of strength `B`. The induced emf between the ends is

Options

A. `B omega R^(2)//2`
B. `2 B omega R^(2)`
C. is variable
D. None of these

Answer

B

Explanation

Here effective length is `2R`
`epsilon=1/2Bomega(2R)^(2)=2BomegaR^(2)`