Question 2 :
An object attached to one end of a spring makes 20 vibrations in 10s. Its frequency is
Question 3 :
When sound waves travel from one medium to another, which of the following physical quantities does NOT alter?
Question 8 :
A sound wave travelling in air is made to propagate through a liquid such that the velocity of sound is quadrupled. If the frequency of he sound wave is constant, find the change in the wavelength of the sound wave.<br>
Question 10 :
A sound wave has a frequency of $10$kHz and wavelength $3$mm. How much time will it take to travel $3$ metre?
Question 11 :
When a wave travels from the one medium to another, the quality which will not change is its
Question 13 :
If the speed of sound is $v$ in gases, then it's speed of sounds in solid will be
Question 14 :
<p>A child inserted a needle in a man's ear.the man became deaf. Why?</p>
Question 15 :
The volume of a cinema theatre is 100m x 60m x 20m and total acoustic absorption in it is 6800metric sabine. The reverberation time in that theatre is<br/>
Question 17 :
In an auditorium or big hall excessive reverberation is highly _______.
Question 19 :
State whether the given statement is True or False :The intensity of an echo is less than that of the original sound.
Question 21 :
Megaphones or loudhailers, horns, musical instruments such as trumpets and  shehnais, are all designed to ______.
Question 23 :
Why do we hear more clearly in a room withcurtains than in a room without curtains?
Question 24 :
Mark the correct statement :i)rock music also becomes less pleasing with excessive reverberation.ii)excessive reverberation is desirable in case of orchestral and choral music. iii)excessive reverberation makes the speech of a person indistinct. 
Question 25 :
The ticking of a watch sounds louder when heard through water than through a metal. True or false.
Question 34 :
The sound heard after reflection from a rigid surface is called echo.
Question 35 :
It is possible to recognize a person by hearing his voice even if he is hidden behind a solid wall. This is due to the fact that his voice:<br/>
Question 36 :
Reverberation time of a hall used for speeches should be very short. Otherwise
Question 37 :
What type of waves are generated by SONAR device fixed to a fishing ship?
Question 38 :
If the guitar and the flute be tunned in the unison then the produced sound can be distinguished by :
Question 39 :
Arrange the materials in the decreasing order of the speed with which sound will travel through them:<br>Metal rod, Air, Water
Question 40 :
Fill the vacant space in the following statement. Sound waves in the range of_____ are best at travelling over large distances.<br/><br/>
Question 45 :
What is the approximate range of audible sound frequencies for a human with good hearing?
Question 46 :
If you go on increasing the stretching force on a wire a guitar, its frequency :<br>
Question 49 :
Sound waves from outside are collected by which part of the ear?