Question

The mutual inductance between a primary and secondary circuit is `0.5H`. The resistance of the primary and the secondary circuits are `20 ohms` and `5ohms` respectvely. To genrate a current of `0.4A` in the secondary,current in the primary must be changed at the rate of
A. `4.0 A//s`
B. `16.0 A//s`
C. `1.6 A//s`
D. `8.0 A//s`

Answer 1

Correct Answer - A
`e_(e)=M(di_(1))/(dt)=0.4xx5=0.5xx(di_(1))/(dt)`
`implies(di_(1))/(dt)=4 A//sec`.