The current through the coil in figure (i) varies as shown in figure (ii). Which graph best shows the ammeter `A` reading as a function of time?

Options

A. (a)
B. (b)
C. ( c)
D. (d)

Answer

A

Explanation

(a) Let `M` is mutual inductance of coil, then the flux in second coil is
`phi_(2) = Mi_(1)` ltbr. `e_(2) = (dphi_(2))/(dt) = M(di_(1))/(dt)`
`i_(2) = (e_(2))/(R ) = (M)/(R )(di)/(dt)` `rarr` `i_(2) prop (di)/(dt)`