Which type of radio signal allows data to be transmitted simultaneously back and forth, like a phone?

Which type of radio signal allows data to be transmitted simultaneously back and forth, like a phone?

• A. Simplex
• B. Duplex
• C. Half-Duplex
• D. Analog

Answer: (B)

Two-way, simultaneous communication is enabled by duplex systems. In radio terms, duplex means the system can transmit and receive at the same time, often using separate frequencies or channels so the two directions don’t interfere. That setup is what makes it feel like a phone call, where you can talk and listen at the same moment. Simplex would be one-way only, so you couldn’t back-and-forth. Half-Duplex allows two-way talk, but not simultaneously—you have to switch between transmitting and listening. Analog describes the signal type (how the data is carried) and doesn’t specify whether two-way communication is possible.

Two-way, simultaneous communication is enabled by duplex systems. In radio terms, duplex means the system can transmit and receive at the same time, often using separate frequencies or channels so the two directions don’t interfere. That setup is what makes it feel like a phone call, where you can talk and listen at the same moment.

Simplex would be one-way only, so you couldn’t back-and-forth. Half-Duplex allows two-way talk, but not simultaneously—you have to switch between transmitting and listening. Analog describes the signal type (how the data is carried) and doesn’t specify whether two-way communication is possible.