Loudness of sound depends upon the condition of …….
a) health
b) brain
c) heart
d) ear
Which type of sound usually old people cannot listen?
a) soft
b) louder
c) shrill
d) grave
Some Common Phenomenon Of Sound:
1.ECHO:
An echo is a repetition or a partial repetition
of a sound due to REFLECTION
When we speak
in a big hall of hilly area or in empty well, we hear our own sound again and
again. What is this phenomenon?
a) shrill
b) graveness
c) echo
d) loudness
Echo is repetition of sound due to reflection of sound waves from a……
a) soft surface
b) hard surface
c) vacuum
d) all of these
To hear echo, sound must reach our ear in how much time?
a) 0.001 second
b) 0.01 second
c) 0.1 second
d) 1 second
