Question

What does a galvanometer measure?Explain.

Answer 1

1. A moving coil galvanometer is an instrument for measuring electric currents.
2. It's a sensitive electromagnetic instrument that can detect extremely low currents, down to a few microamperes.

2. The moving coil galvanometer is composed of a rectangular coil with numerous turns that are often coiled on a metallic frame from thinly insulated or fine copper wire.
3. The coil is free to rotate about a fixed axis.
4. The coil is suspended in a constant radial magnetic field by a phosphor-bronze strip attached to a moveable torsion head.
5. Fundamental properties of the material used for suspension of the coil are conductivity and a low value of the torsional constant.
6. To strengthen the magnetic field and make it radial, a cylindrical soft iron core is placed symmetrically inside the coil.
7. A phosphor-bronze spring with a few twists is used to hold the coil's lower portion in place.
8. The other end of the spring is connected to binding screws.
9. A consistent angular deflection is created by the spring's counter-torque, which balances the magnetic torque.
10. The deflection of the coil is measured using a plane mirror attached to the suspension wire, a lamp setup, and a scale arrangement.
11. The scale's centre represents the Zero-point.
12. A galvanometer is an electric instrument that uses the deflection of a moving coil to measure a tiny electric current.
13. The deflection is a mechanical rotation arising from the current's forces.