What should the approximate resistance of a closed switch be?

The approximate resistance of a closed switch should be zero ohms. When a switch is closed, it is designed to create a complete electrical connection, allowing current to flow freely. This means that the resistance in that state should be minimal, ideally as close to zero as possible.

If a switch has a very high resistance when closed, it is not functioning correctly, leading to potential malfunctions in the circuit it is intended to control. In practical scenarios, a perfectly closed switch might still show a tiny resistance due to the material and design; however, for the purposes of most calculations and definitions, we refer to it as zero ohms. This characteristic ensures that electrical devices can operate efficiently without energy loss or significant voltage drop across the switch itself.