5 Why is the deflection of the needle of a galvanometer smal

5. Why is the deflection of the needle of a galvanometer smaller when the magnet moving past a coil of wire connected to the meter is moved slowly rather than rapidly?

Solution

Galvanometer is an instrument to measure very low currents in the circuit. The accuracy of galvanometer depends on uniform magnetic field or constant magnetic field.

When a magnet moves rapidly towords galvanometer coil, rate of change in magnetic flux linked with the coil is very high.An induced emf developed in the coil which produced varying magnetic fiueld in the galvanometer.Deflection in the coil is larger.

Hence magnet moves slowly towords the galvanometer, rate of change of magnetic flux linked with coil is constant whioch produces uniform magnetic field in the coil. Deflection in the coil is smaller.