Which of these components can be used as an electronic switch?
Varistor
Potentiometer
Transistor✓الإجابة الصحيحة
Thermistor
الشرح
A transistor can be driven fully off or fully on by its control electrode, so it switches current with no moving parts. An adjustable resistive control, a varistor, and a thermistor only vary their resistance and cannot be commanded to a hard on or off state.