Advanced Qualification · A-002 Advanced components and circuits · A-002-006-008
Which class of amplifier provides the least efficiency?
- A Class A
- B Class
- C Class B
- D Class AB
Correct answer: A — Class A. From the official ISED question bank, verified word for word.
Why
Class A amplifiers are the least efficient because they keep the output transistor fully turned on at all times, even when no signal is present, wasting energy as heat. The full explanation — and one for every question — is in Pro.
Practise this section
Advanced components and circuits: semiconductors, amplifier classes, oscillators, mixers, filters and digital logic.