A metal disc of radius R rotates with an angular velcoity `omega` about an axis perpendiclar to its plane passing through its centre in a magnetic field B acting perpendicular to the plane of the disc. Calculate the induced emf between the rim and the axis of the disc.

Options

A. `-(BR^(2)omega)/(2)`
B. `-(2Bpi^(2)R^(2))/(omega^(2))`
C. `-BpiR^(2)omega`
D. `-BpiR^(2)`

Answer

A

Explanation

`e=-BA f=-Bpir^(2)xx(omega)/(2pi)=-(1)/(2)Bomegar^(2)`
`=-(1)/(2)BomegaR^(2)`