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:

Radio waves end where microwaves begin, at 1 GHz. Infrared is 300 GHz to 400 THz.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
In the wireless part of the computer networks chapter, the electromagnetic spectrum is split into radio waves, microwaves and infrared waves. Each type has its own frequency range.

Step 2: Key Formula or Approach:
The standard values given in the textbook are: radio waves 3 KHz to 1 GHz, microwaves 1 GHz to 300 GHz, and infrared waves 300 GHz to 400 THz.

Step 3: Check option 1:
3 KHz to 300 GHz covers radio waves and microwaves together. It is the broad radio frequency spectrum, but it is not the range given for radio waves alone. So option 1 is FALSE here.

Step 4: Check option 2:
1 GHz to 10 GHz lies inside the microwave band. It is not the radio wave range. So option 2 is FALSE.

Step 5: Check option 3:
300 GHz to 400 THz is the infrared range. So option 3 is FALSE.

Step 6: Check option 4:
3 KHz to 1 GHz matches the textbook range of radio waves. So option 4 is TRUE.

Final Answer:
Radio waves range from 3 KHz to 1 GHz. This is option 4. \[ \boxed{4} \]