How many lines can a SPST switch cut?

A Single Pole Single Throw (SPST) switch is designed to control a single circuit by providing on/off functionality for that circuit. This means the switch can interrupt or complete the flow of electricity in just one line, which is essentially the active wire in the circuit that it controls.

In practical terms, an SPST switch has two terminals: one connected to the power source (line) and the other connected to the load (device or appliance). When the switch is in the "on" position, electricity flows through one line to power the device. When switched "off," it breaks this connection, cutting the flow of electricity.

This characteristic makes the SPST switch straightforward and effective for simple on/off applications where only a single line needs to be controlled.