A coil having an area `2m^(2)` is placed in a magnetic field which changes from `1 Wb//m^(2)` to `4Wb//m^(2)` in an interval of `2` second. The average e.m.f. induced in the coil will be

Options

A. 4 V
B. 3 V
C. 1.5 V
D. 2 V

Answer

B

Explanation

Induced emf, `e=-(dphi)/(dt)`
`|e|=(d)/(dt)(BA)=A(dB)/(dt)=2xx((4-1))/(2)=3V`