All of the following items of electrical equipment are devices, except for____.

• A. light bulb
• B. switch
• C. fuse
• D. circuit breaker

Answer: (A)

This question tests the idea that some electrical items actively control or protect a circuit, while others are just loads.

A switch, a fuse, and a circuit breaker all perform a functional action in a circuit: the switch opens or closes the circuit, the fuse interrupts current when it overheats, and the circuit breaker automatically trips to stop current during a fault. These are considered devices because they carry out a specific operational role in the electrical system.

The light bulb, however, is a passive load that converts electrical energy into light (and heat) without performing any control or protective action. It simply consumes power and doesn’t regulate or protect the circuit, so it isn’t categorized as a device in this context.