Advertisements
Advertisements
प्रश्न
Name the device which is used to address a small gathering of people.
Advertisements
उत्तर
Megaphone or bullhorn is a device that is used to address a small gathering of people.
APPEARS IN
संबंधित प्रश्न
The minimum distance between the source and the reflector in air. So that an echo is heard is approximately equal to ______.
The echo of a sound is heard after 5 seconds. If the speed of sound in air be 342 m/s, calculate the distance of the reflecting surface.
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 ?
What is the minimum distance in air required from a sound reflecting surface to hear an echo (at 20°C) ?
A man standing 825 metres away from a cliff (steep rock) fires a gun. After how long will he hear its echo ? Speed of sound in air is 330 m/s.
A man is kidnapped, blindfolded and imprisoned in a big room. How could the man tell if he was in : a furnished room
Answer the following question in your own words.
What is an echo?
What is the minimum distance needed for an echo?
To hear an echo, the minimum distance of the obstacle from the source of sound must be ______.
Assertion: The sound which we hear again is called Echo.
Reason: The sensation of sound (Echo) persists in our brain for about 1 s.
