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प्रश्न
Name the device which is used to address a small gathering of people.
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उत्तर
Megaphone or bullhorn is a device that is used to address a small gathering of people.
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संबंधित प्रश्न
When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?
Fill in the blank with suitable word :
An echo is simply a ................... sound.
On which day, a hot day or a cold day, an echo is heard sooner ? Give reason for your answer.
The speed of sound in water is 1500 metres per second. How far away from an under-sea rock should a deep sea diver be so that he can hear his own echo ?
A man is kidnapped, blindfolded and imprisoned in a big room. How could the man tell if he was in : a furnished 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 ?
A man is standing between two vertical walls 680 m apart. He claps his hands and hears two distinct echoes after 0.9 seconds and 1.1 seconds respectively. What is the speed of sound in the air?
______ is an image obtained by the use of reflected ultrasonic waves.
What is an echo? Write the conditions to hear an echo.
Answer the following question in your own words.
What factors are important to get a distinct echo?
