Which wireless technology is used on smart phones to transmit data to another device within only very close proximity?BluetoothNFC3G/4GWi-Fi

To answer the question about which wireless technology is used on smartphones to transmit data to another device within very close proximity, we will analyze the given options and their characteristics.

1. Bluetooth: This technology allows devices to connect and communicate over short distances, typically ranging from 1 to 100 meters, depending on the class of Bluetooth being used. While it is capable of transmitting data over short distances, it is not limited to very close proximity.

2. NFC (Near Field Communication): NFC is designed for very close-range communication, typically within a distance of 4 centimeters (about 1.5 inches). It is commonly used for mobile payments, data sharing between devices, and pairing connections.

3. 3G/4G: These are cellular technologies used for mobile internet access and require a connection to cellular towers. They are not limited to close proximity and are used for longer-range communication.

4. Wi-Fi: This technology provides wireless internet connectivity over greater distances than Bluetooth or NFC and is not confined to close range.

Final Answer

The correct answer is NFC (Near Field Communication) as it is specifically designed for short-range communication between devices at very close proximity.