السؤال 250What is a relay?An electrically-controlled switch✓الإجابة الصحيحةA current-controlled amplifierAn inverting amplifierA pass transistorالشرحA relay is a switch whose contacts are moved by an electromagnet, so a small control current can open or close a much larger circuit and keep the two electrically separate. It switches rather than amplifies, which rules out the amplifier choices.