A coil has 600 turns which produces `5 xx 10^-3 Wb//turn` of flux when `3 A` current flows in the wire. This produced `6 xx 10^-3` Wb/turn in 1000 turns secondary coil. When the opened, the current drops to zero in `0.2 s` in primary. Find
(a) mutual inductance,
(b) the induced emf in the secondary,
(c) the self-inductance of the primary coil.

Explanation

`N_(1)=600` , `i_(1)=3A`
`N_(2)=1000`
`phi_(2)=Mi_(1)`
`1000xx6xx10^(3)=Mxx3 implies M=2H`
`e=-M(di)/(dt)=-2xx((0-3))/(0.2)=30V phi_(1)=Li_(1)`
`600xx5xx10^(-3)=Lxx3 implies L=1H`