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प्रश्न
Explain by giving a scientific reason.
We cannot hear the echo produced in a classroom.
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उत्तर
- An echo is a sound produced when the original sound is reflected by the walls of a given room. For instance, in a small room If there are hard walls there will be an echo of sound bouncing off the wall but because the sound bouncing is so close to the original, it is harder to detect the echo produced.
- A room which is having a dimension greater than 17.2 m will produce an echo in that room.
- The dimensions of a classroom usually do not exceed 17.2 m, so echo is not produced in a classroom. So, in the case of a classroom, no echo is produced in a classroom.
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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 ______.
Fill in the blank with suitable word :
Echoes are caused by the ...................... of sound.
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Name any two objects which are good reflectors of sound.
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Which of the following device does not work on the multiple reflections of sound waves ?
Answer the following question in your own words.
What is an echo?
What is an echo?
What are the medical applications of echo?
How can you calculate the speed of sound using echo?
When sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound remain the same. Do you hear an echo sound on a hotter day? Justify your answer.
To hear an echo, the minimum distance of the obstacle from the source of sound must be ______.
______ is an image obtained by the use of reflected ultrasonic waves.
Numerical problems:
An echo returned in 3s. What is the distance of the reflecting surface from the source given that the speed of sound is 330 ms-1?
Rohan conducted experiments on echo in different media. He observed that a minimum distance of 'x' meters is required for the echo to be heard in oxygen and 'y' meters in benzene. Compare 'x' and 'y'. Justify your answer.
Speed of sound in oxygen: 340 ms-1
Speed of sound in benzene: 200 ms-1
