Question

which circuit component usually acts as a switch or amplifier?
a. a capacitor
b. a resistor
c. a battery
d. a transistor

Explanation:

A capacitor stores electrical energy. A resistor resists the flow of electric current. A battery provides electrical energy. A transistor can be used as a switch (turning current on or off) or an amplifier (increasing the strength of an electrical signal).

Answer:

D. A transistor