Advanced Qualification · A-002 Advanced components and circuits · A-002-008-008
What are the principal uses of an op-amp RC active filter in amateur circuitry?
- A Op-amp circuits are used as audio filters for receivers
- B Op-amp circuits are used as low-pass filters at the output of transmitters
- C Op-amp circuits are used as filters for smoothing power supply output
- D Op-amp circuits are used as high-pass filters to block RFI at the input of receivers
Correct answer: A — Op-amp circuits are used as audio filters for receivers. From the official ISED question bank, verified word for word.
Why
Op-amp RC active filters are best suited for shaping audio signals inside receivers because they work well at low frequencies without needing large, bulky inductors. 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.