Question

What is the range of frequency for radio waves?

• A. 3 KHz to 300 GHz
• B. 1 GHz to 10 GHz
• C. 300 GHz to 400 Thz
• D. 3 KHz to 1 GHz

Hint:

Electromagnetic spectrum for transmission:
Radio waves: \(3\text{ kHz} - 300\text{ GHz}\).
Microwaves: \(300\text{ MHz} - 300\text{ GHz}\).
Infrared: \(300\text{ GHz} - 400\text{ THz}\).

Answer 1

The Correct Option is A

Concept:
Unguided (wireless) media transmit electromagnetic signals without physical conductors.
The electromagnetic spectrum used for wireless telecommunications spans radio waves, microwaves, and infrared light, categorized by their distinct frequency ranges.

Step 1: Standard Electromagnetic Frequency Classifications:
- Radio waves occupy the frequency range from 3 kHz up to 300 GHz. They are omnidirectional, meaning signals propagate in all directions from the antenna and can penetrate walls.
- Microwaves typically span from 300 MHz (or 1 GHz) up to 300 GHz and are unidirectional, requiring line-of-sight propagation.
- Infrared waves cover 300 GHz to 400 THz, used for short-range communication like remote controls.

Step 2: Conclusion:
According to standard computer networking curriculum (NCERT Class 12 Computer Science), the recognized frequency spectrum designated for radio wave propagation is 3 kHz to 300 GHz.
Final Answer:
The frequency range for radio waves is 3 KHz to 300 GHz. Option (A) is correct.