Describe the roles of the bulb, switch, cell, and voltmeter in a circuit.

Dear student,

The bulb is used in the circuit so that the flow of current is confirmed when it glows.
Switch is use to allow and disallow the flow of current in the circuit whenever necessary.
Cell is used to provide a potential difference between the terminals of the conductor used in a circuit.
Voltmeter is used to measure the potential difference across the two terminals of the battery.

Regards