Question

Cellular phones use radio waves to transmit voice communication in the ……

Hint:

Cellular phones use {radio waves} in the {UHF (Ultra High Frequency) band}, typically between {700 MHz - 2600 MHz} for effective voice and data transmission.

Answer 1

Step 1: Understanding Frequency Bands 
Radio waves are classified into different bands based on their frequency range. 
The main categories include: 
ELF (Extremely Low Frequency): Below 3 kHz 
VLF (Very Low Frequency): 3 kHz - 30 kHz 
LF (Low Frequency): 30 kHz - 300 kHz 
MF (Medium Frequency): 300 kHz - 3 MHz 
HF (High Frequency): 3 MHz - 30 MHz 
VHF (Very High Frequency): 30 MHz - 300 MHz 
UHF (Ultra High Frequency): 300 MHz - 3 GHz 
SHF (Super High Frequency): 3 GHz - 30 GHz 
Step 2: Cellular Communication and the UHF Band 
- Cellular phone networks operate in the Ultra High Frequency (UHF) band, which ranges from 300 MHz to 3 GHz.
- This frequency range is preferred for mobile communication because:
- It allows for long-range transmission with minimal interference.
- It can penetrate obstacles like buildings and walls effectively.
- It supports high-speed data transfer. Step 3: Conclusion 
Since mobile phones primarily use frequencies within 700 MHz - 2600 MHz, they fall within the UHF band.