What device is used to measure small amounts of electrical current through the use of an electromagnet?

The device that measures small amounts of electrical current using an electromagnet is a galvanometer. This instrument operates based on the principle that a current-carrying conductor generates a magnetic field. When an electric current passes through the coil of wire within the galvanometer, it creates a magnetic field, which interacts with a permanent magnet. This interaction causes the coil to rotate, and the angle of rotation is proportional to the amount of current flowing through the device.

Galvanometers are particularly sensitive, making them well-suited for detecting small currents that might be difficult to measure with other devices. They can also be used in various applications, such as in analog meters or as components in more complex measuring instruments. This capability distinguishes a galvanometer from other devices like ammeters, which are designed for measuring larger current ranges, voltmeters that measure voltage, and oscilloscopes which visualize electrical signals rather than directly measure current.