Question

This circuit diagram lacks a basic feature of a circuit.

A circuit diagram with a power source on the left and an open switch on the right.
Which basic feature is missing from the circuit?

an energy source
conducting wires
a switch
a device that uses energy

Answer 1

A device that uses energy (a load) is missing — e.g., a bulb, resistor, or motor. The diagram only shows the source and switch, but no energy-using component.