Three identical coils `A,B` and `C` carrying currents are placed co-axially with their planes parallel to one another. `A` and `C` carry current as shown in figure `B` is kept fixed while `A` and `C` both are moved towards `B` with the same speed. Initially, `B` is equally separated from `A` and `C`. The direction of the induced current in the coil `B` is

Options

A. (a) same as that in coil `A`
B. (b) same as that in coil `B`
C. ( c) zero
D. (d) none of these

Answer

C

Explanation

(c ) Because `A and C` are at equal distance from `B`, and their flux across `B` is in opposite direction, so at any time flux in `B` will be zero. Hence no emf is induced.