Question

A manganin swamp resistance is connected in series with a moving coil ammeter consisting of a milli-ammeter and a suitable shunt in order to

• A. minimize the effect of temperature variation.
• B. reduce the size of the meter
• C. obtain large deflecting torque.
• D. minimize the effect of stray magnetic fields.

Answer 1

The correct option is A minimize the effect of temperature variation.

In the PMMC instruments, as temperature increases, the coil resistance increases with the moving coil to provide temperature compensation.