Which of the following device is full duplex?

Options

A. Mobile phone
B. Walky-talky
C. Loud speaker
D. Radio

Answer

To determine which device is full duplex, we need to understand the definition of full duplex communication. Full duplex refers to the capability of a communication device to transmit and receive data simultaneously.

Let's analyze the options provided:

1. **Mobile Phone**: A mobile phone allows two-way communication where both parties can talk and listen at the same time. This means it can transmit and receive data simultaneously. Therefore, a mobile phone is a full duplex device.

2. **Walkie-Talkie**: A walkie-talkie operates in half duplex mode. This means that when one person is speaking, the other person must wait until the first person has finished before they can respond. Hence, it cannot transmit and receive data simultaneously.

3. **Loudspeaker**: A loudspeaker is primarily a receiving device that converts electrical signals into sound. It does not transmit data, so it cannot be classified as full duplex.

Based on this analysis, the device that is full duplex is the **Mobile Phone**.

### Step-by-Step Solution:
1. **Define Full Duplex**: Understand that full duplex allows simultaneous transmission and reception of data.
2. **Analyze Mobile Phone**: Confirm that a mobile phone allows both parties to talk and listen at the same time.
3. **Analyze Walkie-Talkie**: Recognize that a walkie-talkie only allows one person to speak at a time, making it half duplex.
4. **Analyze Loudspeaker**: Identify that a loudspeaker only receives data and does not transmit, thus it cannot be full duplex.
5. **Conclusion**: Conclude that the mobile phone is the only full duplex device among the options provided.