Question

Astronauts communicate with one another on the moon with the help of.
A. Radio waves
B. Sound waves
C. Ultrasound waves
D. Infrasound waves

Answer 1

Hint: Sound waves travel in air. But there is no air in space for sound to travel. Thus, for communication purposes the astronauts need some devices. These devices convert sound from other forms so that the astronauts can communicate. These devices are based on the waves that can travel in space.

Complete answer:
Sound does not travel in vacuum or space. While, electromagnetic waves like radio waves, light waves, etc. can travel in space. Thus, to communicate with each other during skywalking, astronauts use one of the electromagnetic waves that is radio waves.

In the space suit of astronauts, devices are fixed for communication. The devices include radio microphone and speakers. These microphones convert the sound of the person who is speaking from sound to radio waves. Then the speaker converts this radio wave to sound wave so that the other astronaut can hear. This is how astronauts communicate with each other on the moon or at a point in space. Astronauts use the same devices to communicate with people on the ground. These sounds get converted to radio waves because of the air in the space suit.

Thus, astronauts communicate with one another on the moon with the help of radio waves.

So, the correct answer is “Option A”.

Note:
Just after the Big bang, the universe was dense enough for the sound to travel in space. As the universe is expanding, volume is increasing. Thus, the density of the universe is decreasing. Due to which, travel of sound waves in the universe is not possible.