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प्रश्न
What is meant by an echo?
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उत्तर १
If a person stands at some distance from a wall or a hillside and produces a sharp sound, he hears two distinct sounds: one is original sound heard almost instantaneously and the other one is heard after reflection from the wall or hillside, which is called echo.
उत्तर २
The sound that keeps coming after reflecting off of a hard surface (such a cliff, a hillside, a building's wall, or the edge of a forest). It's referred to as an echo.
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संबंधित प्रश्न
The minimum distance between the source and the reflector in air. So that an echo is heard is approximately equal to ______.
Name three devices which work on the reflection of sound.
What is the other name of a loud-hailer ?
Name the device which is used to address a small gathering of people.
On which day, a hot day or a cold day, an echo is heard sooner ? Give reason for your answer.
In which medium, air or water, an echo is heard much sooner ? Why ?
A man is kidnapped, blindfolded and imprisoned in a big room. How could the man tell if he was in : a bare room
An echo-sounder in a trawler (fishing boat) receives an echo from a shoal of fish 0.4 s after it was sent. If the speed of sound in water is 1500 m/s, how deep is the shoal ?
State two conditions necessary for hearing an echo.
Assertion: The sound which we hear again is called Echo.
Reason: The sensation of sound (Echo) persists in our brain for about 1 s.
