What is the purpose of a shunt in an ammeter?

The purpose of a shunt in an ammeter is to carry current around the meter movement. An ammeter is designed to measure current flowing in a circuit, and it typically includes a sensitive measurement mechanism that would be damaged or produce inaccurate readings if subjected to high currents. To protect this delicate part of the ammeter, a shunt resistor is used, which allows most of the current to bypass the main meter movement.

The shunt creates a parallel path for current. By directing the larger portion of the current through the shunt, the meter movement can measure the smaller current that is safely passed through its sensitive mechanism. The design allows for accurate readings without jeopardizing the functionality of the ammeter, making it essential for measuring high currents without causing damage. The use of a shunt enables the ammeter to measure a wide range of current levels effectively.