Transistors Flashcards
(8 cards)
What is the main function of an NPN transistor when used as a switch?
To control a large current flowing between the collector and emitter by applying a small current to the base.
How does an NPN transistor act as a switch in a circuit?
When a small current is applied to the base, it allows a larger current to flow from collector to emitter, turning the switch ‘on’.
What are the three terminals of an NPN transistor?
Base, collector, and emitter.
Which terminal controls the transistor’s switching action?
The base.
Where does the main current flow in an NPN transistor?
From collector to emitter.
How do you identify the base, emitter, and collector on the NPN transistor symbol?
The base is the middle line, the emitter is the arrowed line (arrow points out), and the collector is the other line.
What happens when no current is applied to the base?
The transistor switches off and no current flows from collector to emitter.
Give one common application of an NPN transistor as a switch.
Controlling LEDs, motors, or relays in electronic circuits.
