The feeling of original sound remains in our brain till …….
a) 0.001 second
b) 0.01 second
c) 0.1 second
d) 1 second
When our brain cannot recognize original sound and its echo?
a) when reflected sound waves reach our ear before 1 second
b) when reflected sound waves reach our ear before 10 second
c) when reflected sound waves reach our ear before 0.1 second
d) when reflected sound waves reach our ear before 0.2 second
What should be the minimum distance between the speaker and reflecting surface?
a) 10 m
b) 1000 m
c) 100 m
d) 17 m
What is the speed of sound in air?
a) zero
b) 340 m/s
c) 240 m/s
d) 140 m/s
What is the speed of sound in vacuum?
a) zero
b) 340 m/s
c) 240 m/s
d) 140 m/s
2. HEARING THUNDER AFTER LIGHTENING:
Thunder
will always be heard after the lightning strike is seen owing to the fact that
light travels significantly faster than sound.
