Question

Moving coil galvanometer operates on Permanent Magnet Moving Coll (PMMC) mechanism.

Moving coil galvanometers are of two types
(a) Suspended coll
(b) Pivoted coil type or tangent galvanometer,

Its working is based on the fact that when a current carrying coil is placed in a magnetic field, it experiences a torque. This torque tends to rotate the coil about its axis of suspension in such a way that the magnetic flux passing through the coil is maximum.

$\left(iv\right)$ In a moving coil galvanometer, having a coil of $N$-turns of area $A$ and carrying current $I$ is placed in a radial field of strength $B$. The torque acting on the coil is

• A. $N{A}^2{B}^{2}I$
• B. $NAB{I}^2$
• C. $N^{2}ABI$
• D. $NABI$

Answer 1

The correct option is D $NABI$

The deflecting torque acting on the coil is $\tau =NIAB$