Two coils have mutual inductance of 1.5 henry. If current in primary circuit is raised to 5 ampere in one millisecond after closing the circuit, what is the e.m.f. Induced in the secondary ?

Options

A. 30 kV
B. 60 kV
C. 90 V
D. 45 V

Answer

A

Explanation

Given, mutual inductance, M=10 H
change in current, dI=3A
change in time, dt=1 millisecond`=10^(-3)s`
Emf induced, `e_(s)=?`
emf induced in secondary coil,
`e_(s)=(MdI)/(dt)`
On putting the values, we get
induced emf`=(10xx3)/(10^(-3))`
`=3xx10^(4)V`
`e_(s)30kV`