Four sources of sound each of sound level 10 dB are sounded together in phase, the resultant intensity level will be ($log _{10}2 = 0.3$)

Consider ten identical sources of sound all giving the same frequency but having phase angles which are random. If the average intensity of each source is $I _{0}$, the average of resultant intensity $I$ due to all these ten sources will be

Two sources of sound A and B produce the wave of $350Hz$, they vibrate in the same phase. The particle $P$ is vibrating under the influence of these two waves. If the amplitude at the point $P$ produced by the two waves is $0.3mm$ and $0.4mm$ then the resultant amplitude of the point $P$ will be: (path difference $AP-BP=25cm$ and the velocity of sound is $350m/sec$)

Two plane harmonic sound waves travelling in the same direction are given by the following displacement equations
$y _{1} (x, t) = A\cos (0.5\pi x - 100\pi t)$
$y _{2} (x, 1) = A\cos (0.46\pi x - 92\pi t)$
How may times, a listener can hear sound of maximum intensity in one second?

 When two sound waves with a phase of $\dfrac { \pi  }{ 2 } $ and each having amplitude A and frequency $\omega $, are superimposed on each other, then the maximum amplitude and frequency  of resultant wave is: 

Two waves having the intensities in the ratio 9 : 1 produce interference. The ratio of maximum to minimum intensity is equal to

Two waves $Y _{1}= asin\omega t$  and $Y _{2}= asin(\omega t+\delta )$  are  producing interference, then resultent intensity is 

Beats are produced because of the superposition of two progressive notes> Maximum loudness at the waxing is $n$ times the loudness of either notes. What is the values of $n$?

If a tuning fork sends a wave $5 sin \displaystyle \left(600\omega t - \frac{\pi}{0.6}x \right)$, then the amplitude of the intensity heard is

Two identical sources of sound of same frequency and identical intensities $\displaystyle I _0$ are producing sound. If their phases are irregular, then the average intensity of sound at a point where waves from the two sources are superposing is 

When interference is produced by two progressive waves of equal frequencies, then the maximum intensity of the resulting sound are N times the intensity of each of the component waves. The value of N is

Two coherent sources of intensity ratio $\alpha$ interfere. In interference pattern $\dfrac{{I} _{max} - {I} _{min}}{{I} _{max} + {I} _{min}} =$

In case of super position of waves (at $x=0$),
 $y _{1}=4\sin(1026\pi t)$ and $y _{2}=2\sin(1014\pi t)$


a) the frequency of resulting wave is $510$ Hz
b) the amplitude of resulting wave varies at the frequency of $3$ Hz
c) the frequency of beats is $6$ per second
d) the ratio of maximum to minimum intensity is $9$

If an observer is walking away from the plane mirror with $6 m/sec$. Then the velocity of the image with respect to the observer will be

A loudspeaker that produces signals from $50Hz$ to $500Hz$ is placed at the open end of a closed tube of length $1.1m.$ If velocity of sound is $330m/s,$ then frequencies that excites resonance in the tube are: