The purpose of soft iron cylinder between the pole pieces of the horse`-` shoe magnet in a moving coil galvanometer is

Options

A. increase space for rotation of coil
B. reduce weight of galvanometer
C. produce magnetic field which is parallel to plane of coil at any position
D. make magnetic induction weak at the centre.

Answer

C

Explanation

The horseshoe magnet has cylindrically concave pole pieces . Due to its shape the magnet produces radial magnetic field, so that when the coil rotates in any position its plane is always parallel to the direction of the magnetic field. This has been shown in the figure given below.