An electromagnetic relay is used in some electrical circuits. What is its primary function?
to increase alternating voltage from a low value to a high value
to protect a circuit by opening the contacts when the current is too large
to use a small current in one circuit to switch on a larger current in another circuit
to convert alternating current (AC) into direct current (DC)
67 exam-style questions on CIE IGCSE Physics 4.3.3 Action and use of circuit components. Each one has a worked solution and a mark scheme showing where the marks go.