# How does a moving coil galvanometer measure current?

## How does a moving coil galvanometer measure current?

Moving coil galvanometer is an electromagnetic device that can measure small values of current. It consists of permanent horseshoe magnets, coil, soft iron core, pivoted spring, non-metallic frame, scale, and pointer. Torque acts on a current carrying coil suspended in the uniform magnetic field.

How does a galvanometer work as an actuator?

A galvanometer works as an actuator, by producing a rotary deflection (of a “pointer”), in response to electric current flowing through a coil in a constant magnetic field.

### How is the deflection of a moving coil measured?

The hemispherical magnetic poles produce a radial magnetic field in which the plane of the coil is parallel to the magnetic field in all its positions. A small plane mirror attached to the suspension wire is used along with a lamp and scale arrangement to measure the deflection of the coil.

What kind of instrument is a galvanometer used for?

In short, it uses an electric meter. The galvanometer is an instrument used to determine the presence, direction, and strength of an electric current in a conductor.

#### How is the deflection of a galvanometer measured?

In a suspended coil galvanometer, the coil is suspended by a thin phosphor bronze strip and the deflection of the coil is measured by a lamp and a scale arrangement. A suspended coil galvanometer can measure currents of the order of 10 -9 A.

How is a soft iron core used in a galvanometer?

Solution: The cylindrical soft iron core placed inside the galvanometer increases the magnetic field strength, thereby improving the sensitivity of the instrument. It also makes the magnetic field radial so that the angle between the plane of the coil and the magnetic lines of force remains zero at all times during the rotation of the coil.