Basic Qualification · B-008 Interference and suppression · B-008-005-003
What type of filter attenuates RF energy above and below a certain range of frequencies?
- A Band-pass
- B High-pass
- C Notch
- D Low-pass
Correct answer: A — Band-pass. From the official ISED question bank, verified word for word.
Why
A band-pass filter lets signals through only within a specific range of frequencies, blocking anything too low or too high. The full explanation — and one for every question — is in Pro.
Practise this section
When things interfere: harmonics, overload, RFI to and from your station, filters, ferrites and how to fix the neighbour's TV.