It conducts vibrations from speaker to receiver. It magnifies a person's voice. It carries the sounds through wires. It converts vibrations to electrical signals.
I gave my students this multiple choice question: How is a telephone able to transmit sound?

Only one answer is correct among these 4 choices:
- It conducts vibrations from speaker to receiver.
- It magnifies a person's voice.
- It carries the sounds through wires.
- It converts vibrations to electrical signals.

Could you tell me which one is correct?

It converts vibrations to electrical signals.