Sound Waves

Question 1

Difference between em radiation and sound Waves.

Answer 1

sound waves require a medium to travel, electromagnetic waves do not. Sound waves also do carry energy when traveling, which is done by EM waves. While sound waves only act as waves, EM waves act as waves as well as particles.

Question 2

How electromagnetic waves are converted into sound waves in a radio

Answer 2

1. Electromagnetic waves (radio signals) are transmitted through the air.
2. The radio receiver picks up these waves using an antenna.
3. The received signal is sent to a tuner, which filters out all frequencies except the desired one.
4. The filtered signal is then amplified by an amplifier.
5. The amplified signal is sent to a detector (demodulator), which extracts the original information (audio signal) from the carrier wave.
6. The audio signal is then sent to a speaker.
7. The speaker converts the electrical audio signal into mechanical vibrations (sound waves) using a magnetic coil and a diaphragm.
8. These sound waves are what we hear as sound coming from the radio!

In more detail:

• The detector (demodulator) uses a process called amplitude modulation (AM) or frequency modulation (FM) to extract the audio signal.
• The audio signal is then sent to a low-pass filter to remove any remaining high-frequency components.
• The filtered audio signal is amplified again before being sent to the speaker.
• The speaker’s magnetic coil converts the electrical signal into magnetic fields, which move the diaphragm back and forth.
• The diaphragm’s vibrations push and pull air molecules, creating sound waves that our ears pick up