Basic Qualification · B-004 Circuit components · B-004-004-006
Why is a field-effect transistor considered a high impedance device?
- A It uses high resistance semiconductors
- B It functions at low voltage
- C It functions at high current
- D The gate never conducts current
Correct answer: D — The gate never conducts current. From the official ISED question bank, verified word for word.
Why
A field-effect transistor is called a high impedance device because its gate terminal acts like an insulator, meaning almost no electrical current flows into it during normal operation. 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.