Step-by-step explanation:
Galvanometer: It is a device which shows deflection when the current flows in the circuit. If it does not show any deflection, then it means that the current is not flowing in the circuit.
There is a magnetic field around the current carrying conductor.
It is developed from the observation that the needle of the compass shows deflection near the current carrying wire.
Galvanometer: It consists of compass needle attached to a coil. The coil is allowed to pivot freely in the uniform magnetic field. The magnetic field is created by the poles of the permanent magnet.
In galvanometer,the torque on a current loop in uniform magnetic field is used to measure magnetic field.