A flat coil of radius 0.7 cm has 100 loops. It is placed in a magnetic field of induction 0.3 T so that no flux passes through it. Then it is rotated such that maximum flux passes through it in 0.02 s. the induced emf in the coil is

Options

A. 0.15 V
B. 0.73 V
C. 0.23 V
D. 4.14 V

Answer

C

Explanation

`e=(dphi)/(dt)=(nAB)/(dt)=(npir^(2)B)/(dt)`
`=(100xx3.14xx0.49xx10^(-4)xx0.3)/(0.02)`
`=0.23V`