Consider the following statements about the microphone and the speaker

Consider the following statements about the microphone and the speaker of a mobile phone :

  • 1. The microphone converts sound to a mechanical signal.
  • 2. The microphone converts sound to an electrical signal.
  • 3. The speaker converts a mechanical signal to sound.
  • 4. The speaker converts an electrical signal to sound.

Which of the statements given above are correct?

1 and 3
1 and 4
2 and 3
2 and 4
This question was previously asked in
UPSC CDS-1 – 2023
A microphone is a transducer that converts sound waves (acoustic energy) into electrical signals. This electrical signal is then processed. A speaker is also a transducer that converts an electrical signal back into sound waves (acoustic energy). Therefore, statement 2 (microphone converts sound to an electrical signal) and statement 4 (speaker converts an electrical signal to sound) are correct. Statements 1 and 3 involving “mechanical signal” in this context are incorrect as the primary conversion involves energy forms like sound and electricity, mediated by mechanical *vibrations* but the output/input are electrical/sound signals.
Microphones convert sound energy into electrical energy. Speakers convert electrical energy into sound energy.
Microphones typically work by diaphragm vibration caused by sound waves, which then generates an electrical signal (e.g., carbon, dynamic, condenser microphones). Speakers work by an electrical current flowing through a coil in a magnetic field, causing the coil (and an attached diaphragm/cone) to vibrate, producing sound waves.