EASY
9th CBSE
IMPORTANT
Earn 100

Name any two objects which are good reflectors of sound.

Important Questions on Sound

MEDIUM
9th CBSE
IMPORTANT
State the laws of reflection of sound.
EASY
9th CBSE
IMPORTANT
What is an echo? How is echo formed?
EASY
9th CBSE
IMPORTANT
What is the minimum distance in the air required from a sound-reflecting surface to hear an echo (at 20 °C)?
EASY
9th CBSE
IMPORTANT
A man standing 825 meters away from a cliff (steep rock) fires a gun. After how long will he hear its echo? The Speed of sound in air is 330 ms.
MEDIUM
9th CBSE
IMPORTANT
What is ultrasound? What is the difference between ordinary sound and ultrasound?
MEDIUM
9th CBSE
IMPORTANT
Write any three applications (or uses) of ultrasound.
MEDIUM
9th CBSE
IMPORTANT
What are infrasonic waves? Name two animals which produce infrasonic waves.
MEDIUM
9th CBSE
IMPORTANT
What are ultrasonic waves? Name two animals which can produce ultrasonic waves.