A coil having an area `A_(0)` is placed in a magnetic field which changes from `B_(0)` to `4B_(0)` in time interval t. The emf induced in the coil will be

Options

A. `3A_(0)B_(0)//t`
B. `4A_(0)B_(0)//t`
C. `3B_(0)//A_(0)t`
D. `4B_(0)//A_(0)t`

Answer

A

Explanation

As, `|e|=(Deltaphi)/(Deltat)=(4B_(0)A_(0)-B_(0)A_(0))/(t)=(3B_(0)A_(0))/(t)`