11-04-2017, 11:07 AM
A Helmholtz galvanometer, like other galvanometers, is an instrument that can be used to measure the DC current in the circuit. It is an improved form of the galvanometer tangent. It is based on the Tangent Law, which states that when two magnetic fields are acting perpendicular to each other, then for a given deviation field restoration field is directly proportional to the tangent of the angle made by the resulting field with the restoration field. That the magnetic field produced by the coils in ninety degrees to the horizontal component of the earth's magnetic field. A plane passing through the axis of the magnetic needle suspended freely through its center of gravity and is at rest under the earth's magnetic field.
