What is the difference between Bluetooth and Wi-Fi devices ?
A
Bluetooth uses 2-4 GHz radio frequency band, whereas Wi-Fi can use 2-4 GHz or 5 GHz frequency band
B
Bluetooth is used for Wireless Local Area Networks (WLAN) only, whereas Wi-Fi is used for Wireless Wide Area Networks (WWAN) only
C
When information is transmitted between two devices using Bluetooth technology, the devices have to be in the line of sight of each other, but when Wi-Fi technology is used the devices need not be in the line of sight of each other
D
The statements (a) and (b) given above are correct in this context
Correct Answer: Option A
Explanation
1. Statement (A) is correct: Bluetooth primarily operates in the 2.4 GHz ISM (Industrial, Scientific, and Medical) radio frequency band. Wi-Fi devices commonly operate in both the 2.4 GHz and 5 GHz frequency bands (and increasingly, 6 GHz with Wi-Fi 6E). This is a key technical difference.
2. Statement (B) is incorrect: Bluetooth is typically used for creating short-range Wireless Personal Area Networks (WPANs) connecting devices like headphones, keyboards, etc., not Wireless Local Area Networks (WLAN). Wi-Fi is specifically designed for creating WLANs, providing internet access and local network connectivity within a limited area. Wi-Fi is not typically used for Wireless Wide Area Networks (WWAN), which usually rely on cellular technologies (like 4G, 5G).
3. Statement (C) is incorrect: Neither Bluetooth nor Wi-Fi requires the devices to be in the line of sight of each other. Both use radio waves, which can penetrate obstacles like walls, although range and signal strength can be affected.
4. Statement (D) is incorrect because statement (B) is incorrect.
Therefore, only statement (A) correctly describes a significant difference between Bluetooth and Wi-Fi devices.