Two coils `X` and `Y` are linked such that emf `E` is induced in `Y` when the current in `X` is changing at the rate `I' (= dI//dt)`. If a current `I_(0)` is now made to flow through `Y`, the flux linked with `X` will be

Options

A. `(epsilon//I)i`
B. `epsilon iI`
C. `(epsilon I)i`
D. `iI//epsilon`

Answer

A

Explanation

Let M = mutual inductance between A and B.
`epsilon_(B)=M(di_(A))/(dt)` or `epsilon_(B)=MI` or `M=epsilon_(B)//I`
where `I=di_(A)//dt`
`phi_(A)=Mi_(B)=(epsilon_(B)//I)i_(B)`
`therefore phi_(A)=(epsilon//I)i(i=i_(B))`