Basic Qualification · B-004 Circuit components · B-004-005-006
Which electrode of a vacuum triode is the control element?
- A Emitter
- B Cathode
- C Plate
- D Grid
Correct answer: D — Grid. From the official ISED question bank, verified word for word.
Why
The Grid is the control element in a vacuum triode because it sits between the cathode and the plate, acting like a valve that regulates how many electrons flow through the tube to create an amplified signal. The full explanation — and one for every question — is in Pro.
Practise this section
The parts inside the box: resistors, capacitors, inductors, diodes, transistors, tubes and what each does in a circuit.