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
Fill in the blank with suitable word :
An echo is simply a ................... sound.
What is an echo ? How is echo formed ?
What is the minimum distance in air required from a sound reflecting surface to hear an echo (at 20°C) ?
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?
State two conditions necessary for hearing 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.
What is an echo? Write the conditions to hear an echo.
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
