A round galvanometer is an instrument used to measure small electric currents. It consists of a circular coil of wire suspended between the poles of a permanent magnet, which produces a magnetic field perpendicular to the plane of the coil.

When a current is passed through the coil, it experiences a torque proportional to the strength of the magnetic field and the current, causing it to rotate. This rotation is detected by a pointer attached to the coil, which indicates the current on a calibrated scale.

Round galvanometers are often used in physics and electronics laboratories to measure current in circuits.