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प्रश्न
How is it that bats are able to fly at night without colliding with other objects ?
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उत्तर
Bats are able to fly at night without colliding with other objects because they emit ultrasonic squeaks and listen to the echoes produced by the reflection of their squeaks from the objects or obstacles in their path. Bats can judge the distance of the object in their path and avoid it by changing the direction using the time taken by the echo to be heard after reflection from the obstacle.
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संबंधित प्रश्न
A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.
Explain the term 'amplitude' of a wave. Draw the diagram of a wave and mark its amplitude on it.
Name the unit used to measure the loudness of sound. Also write its symbol.
What name is given to sound waves of frequencies higher than 20 kHz ?
Draw labelled diagrams to represent sound of (a) low pitch, and (b) high pitch, of the same loudness.
What is meant by the quality (or timbre) of sound ? On what factor does the quality (or timbre) of a sound depend ?
Give one use of ultrasound in industry and one in hospitals.
Explain how, bats use ultrasound to catch the prey.
What is sonar ? Explain its use.
A sonar station picks up a return signal after 3 seconds. How far away is the object ? (Speed of sound in water = 1440 m/s).
