For the academic purpose, the University will provide its own 24 x 7 FM channel within the University Campus. Which communication medium, out of the following, is used by FM ?
For the academic purpose, the University will provide its own 24 x 7 FM channel within the University Campus. Which communication medium, out of the following, is used by FM ?
Options
Official answer
Correct option: (A) Radio Waves.
FM (Frequency Modulation) radio broadcasting is transmitted using radio waves, which are omnidirectional, can penetrate walls, and cover a wide broadcast area — exactly suited to a campus-wide 24x7 FM channel.
Marking scheme
- 1.1 mark: for correctly selecting option (A) Radio Waves.
Hint
FM stands for Frequency Modulation — think of the everyday FM radio band, which belongs to the radio-wave part of the spectrum.
Quick oral answer
FM broadcasting uses radio waves because they are omnidirectional and can pass through walls, allowing a single transmitter to cover the whole campus without needing line-of-sight.
Common mistakes
- 1.Confusing microwaves (used for point-to-point, line-of-sight links like satellites/mobile towers) with radio waves used for broadcast media like FM/AM radio.
- 2.Assuming infrared (used in remote controls, very short range) could be used for a campus-wide broadcast.
Analysis and explanation
This MCQ tests recognition of which unguided medium each common technology actually uses.
Why (A) is correct: FM radio operates in the VHF (Very High Frequency) band of the radio spectrum; radio waves are omnidirectional and can travel through obstacles like walls, making them ideal for broadcasting an FM signal across an entire campus without needing line-of-sight.
Why (B) is wrong: Microwaves are used for line-of-sight, point-to-point communication (e.g. satellite links, mobile towers) and cannot bend around obstacles the way radio waves can — unsuitable for an omnidirectional FM broadcast.
Why (C) is wrong: Infrared waves need direct line-of-sight over very short distances (e.g. TV remote controls) and cannot pass through walls at all, making them completely unsuitable for a campus-wide FM broadcast.
Interesting facts
FM radio broadcasting was invented by Edwin Armstrong in 1933, primarily to eliminate the static interference common in AM radio.
Radio waves can travel through walls and do not require line-of-sight, which is why they are used for broadcast radio, Wi-Fi and Bluetooth, unlike microwaves and infrared.
Question details
Q47 of 48 questions
- Board
- CBSE
- Class
- Class 12
- Subject
- Computer Science
- Year
- 2026
- Section
- Section E
- Marks
- 1
- Type
- MCQ
- Chapter
- Computer Networks
- Topic
- Wireless Transmission Media — Radio Waves
- Bloom's level
- remember
- Syllabus topic
- Unit 2: Computer Networks — Wireless/unguided transmission media: radio waves, microwaves and infrared waves and their typical uses
- Author
- CBSE
- Reviewed by
- Padhantu Academic Team
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Frequently asked questions
Could FM ever use microwaves instead of radio waves?
No — FM broadcasting is specifically defined within the radio-wave portion of the electromagnetic spectrum (VHF band); microwaves are a distinct, higher-frequency band used for different applications like satellite and point-to-point links.
Why can't infrared cover a whole campus?
Infrared signals require unobstructed line-of-sight and are absorbed by walls and other solid objects, limiting them to very short-range uses such as remote controls, unlike radio waves which penetrate obstacles easily.