Question 3 :
Fill in the blank.The time taken by ___ oscillation  to complete is called time period. 

Question 5 :
In an auditorium the big curtain when falls&#160;suddenly then the reverberation time<br/>

Question 6 :
If you go on increasing the stretching force on a wire a guitar, its frequency :<br>

Question 8 :
<p>If the speed of light in a medium at a given temperature is 348m/s at a pressure of 2atm. Now the pressure is increased to 5 atm, temperature remaining constant. Now the speed of sound in the same medium will be:</p>

Question 9 :
The persistence of sound in a closed enclosure, due to continuous reflections at the walls, even after the source has stopped producing sound is known as

Question 11 :
What is the approximate range of audible sound frequencies for a human with good hearing?

Question 15 :
Under similar conditions, in which of the following gases will the speed of sound be the least ?

Question 17 :
A man standing between two cliffs hears the first echo of a sound after 2 sec and the second echo 3 sec after the initial sound. If the speed of sound be $330 {m}/{sec}$ the distance between the two cliffs should be

Question 18 :
A sonometer wire, $100\ \text{cm}$ in length has a fundamental frequency of $330\ \text{Hz}$. The velocity of propagation of transverse waves along this wire is :<br/>

Question 20 :
A person bangs on a copper pipe that is part of a large warehouse. The sound can be heard in the pipe $100.0$ meters away in $0.02174$ seconds.<br>If the frequency of the sound is $500.0\ Hz$, what is the wavelength of the second wave in the copper pipe?

Question 21 :
Assertion: When we start filling an empty bucket with water, the pitch of sound produced goes on decreasing. Reason: The frequency of man voice is usually higher than that of woman.

Question 22 :
A man standing in front of a mountain at a certain&#160;distance beats a drum at regular intervals. The&#160;drumming rate is gradually increased and he finds&#160;that the echo is not heard distinctly when the&#160;rate becomes $40$ per minute. He then moves&#160;nearer to the mountain by $90$ m and finds the&#160;echo is again not heard when the drumming rate&#160;becomes $60$ per minute. <br/>(a) The distance&#160;between the mountain and the initial position of&#160;the man and&#160;(b) The velocity of sound are:<br/>

Question 23 :
On sending an ultrasonic wave form a ship towards the bottom of a sea, the time interval between sending&#160;the wave and receiving it back is found to be 1.5 s.&#160;If the velocity of wave in sea water is 1400 $ms^{-1}$&#160;find the depth of the sea.

Question 24 :
A man standing $25$ m away from a wall produces a sound and receives the reflected sound.&#160;Calculate the time in seconds&#160;after which he receives the reflected sound if the speed of sound in air is $350$ $ms^{-1}$.

Question 25 :
The frequency of a fork is $200$ Hz. The distance through which sound travels by the time the fork make $16$ vibrations is(velocity of sound in air is $340$ m/s).