Two coils P and Q are at fixed position. When coil P has no current in coil Q increases at the rate of `5As^(-1)`, the e.m.f. in coil P is 20 mV. What is the mutual inductance? When the coil Q has no current and coil P has a current of 3A, what is the flux linkage in coil Q?

Explanation

`varepsilon_(1)=M(di_(2))/(dt)," "varepsilon_(1)=20xx10^(-3)V, (di_(2))/(dt)=5As^(-1)`
`M=(varepsilon_(1))/(((di_(2))/(dt)))=(20xx10^(-3))/(5)=4mH`
Flux linkage in coil `Q=N_(Q).phi_(QP)=M.i_(1)=4xx10^(-3)xx3=12xx10^(-3)` weber