Question

Explain in brief the basic construction of a moving-coil table galvanometer whit a neat labelled diagram.

Answer 1

A table galvanometer is made out of a light, rectangular aluminium frame wound with a large number of turns of fine, insulated copper wire. The coil revolves between the cylindrically concave pole sections of a powerful horseshoe-shaped permanent magnet and is equipped with a pointer. A cylindrical soft iron core positioned in between the pole parts allows the coil to freely swing around it. The current flowing through the galvanometer (or the potential difference across it) determines the coil's deflection. A spiral spring stops the coil's deflection, which is then measured using a scale pointer.

A table galvanometer (Schematic diagram)