Basic Qualification · B-004 Circuit components · B-004-005-002
Which two elements of a triode carry the output current?
- ACathode and plate
- BCathode and grid
- CEmitter and collector
- DSource and drain
Correct answer: A — Cathode and plate. From the official ISED question bank, verified word for word.
Why
In a triode vacuum tube, the cathode heats up to release electrons, which then travel across the empty space to land on the positively charged plate, creating the main output current. The full explanation — and one for every question — is in Pro.
Practise this section
Circuit components is section B-004 of the Basic exam: The parts inside the box: resistors, capacitors, inductors, diodes, transistors, tubes and what each does in a circuit.
Drill B-004 — free, no account