Advertisements
Advertisements
प्रश्न
Answer the following question in your own words.
What is an echo?
उत्तर
An echo is the reflection of sound waves off a surface, such as a wall, mountain, or building, that returns to the listener after a delay. It occurs when the reflected sound reaches the ear after at least 0.1 seconds, allowing the listener to distinguish it from the original sound. Echoes are commonly experienced in large, empty spaces or near hard, smooth surfaces.
APPEARS IN
संबंधित प्रश्न
Does sound follow the same laws of reflection as light does? Explain.
The minimum distance between the source and the reflector in air. So that an echo is heard is approximately equal to ______.
What is the other name of a loud-hailer ?
Fill in the blank with suitable word :
An echo is simply a ................... sound.
Fill in the blank with suitable word :
Echoes are caused by the ...................... of sound.
In which medium, air or water, an echo is heard much sooner ? Why ?
Why do we hear more clearly in a room with curtains than in a room without curtains ?
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 ?
State the laws of reflection of sound.
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.
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 ?
The frequencies of four sound waves are given below. Which of these sound waves can be used to measure the depth of sea by the echo method ?
Which of the following device does not work on the multiple reflections of sound waves ?
Explain by giving a scientific reason.
We cannot hear the echo produced in a classroom.
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?
What are the medical applications of echo?
How can you calculate the speed of sound using echo?
______ allows bats to navigate through dark caves and find insects for food.
______ is an image obtained by the use of reflected ultrasonic waves.
