Question

Phosphor-bronze is used for making suspension wire or hair springs, because it is ​

Answer 1

Answer:

Moving coil galvanometer, made on the basis of torque of magnetic field on small circuit.

If torque is T for 'twist constant' c and deflection angle x then T=cx.

Also, T=INBAB= magnetic intensity, I= flow of current in the coil,

N= number of loops, A= Area of the coil.

INBA=cx

For unit flow, x=NBA/c

So in order to get large deflection, c i.e. twist per unit deflection has to be small.

Phosphor-Bronze wire is used for suspension in a moving coil galvanometer because it has small restoring torque per unit twist and high tensile strength.