Q. No.Two sources of sound placed close to each other, are emitting progressive waves given by,
\(y_1=4\sin 600\pi t\) and \(y_2=5\sin 608\pi t\).
An observer located near these two sources of sound will hear:
1.
\(4\) beats per second with intensity ratio \(25:16\) between waxing and waning
2.
\(8\) beats per second with intensity ratio \(25:16\) between waxing and waning
3.
\(8\) beats per second with intensity ratio \(81:1\) between waxing and waning
4.
\(4\) beats per second with intensity ratio \(81:1\) between waxing and waning
\(y_1=4\sin 600\pi t\) and \(y_2=5\sin 608\pi t\).
An observer located near these two sources of sound will hear:
\(y_2 = a\cos(\omega t+kx)~\text{m},\) where \(x\) is in meters and \(t\) in seconds. The phase difference between them is:
1. \(1.25\) rad
2. \(1.57\) rad
3. \(0.57\) rad
4. \(1.0\) rad
| 1. | increase by a factor of \(20\). |
| 2. | increase by a factor of \(10\). |
| 3. | decrease by a factor of \(20\). |
| 4. | decrease by a factor of \(10\). |
A transverse wave is represented by y = Asin(ωt -kx). At what value of the wavelength is the wave velocity equal to the maximum particle velocity?
1. A/2
2. A
3. 2A
4. A
A tuning fork of frequency \(512~\text{Hz}\) makes \(4~\text{beats/s}\) with the vibrating string of a piano. The beat frequency decreases to \(2~\text{beats/s}\) when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was:
1. \(510~\text{Hz}\)
2. \(514~\text{Hz}\)
3. \(516~\text{Hz}\)
4. \(508~\text{Hz}\)
1. \(y =(0.02~\text{m})\sin(7.85x+1005t)\)
2. \(y =(0.02~\text{m})\sin(15.7x-2010t)\)
3. \(y =(0.02~\text{m})\sin(15.7x+2010t)\)
4. \(y =(0.02~\text{m})\sin(7.85x-1005t)\)
The driver of a car travelling at a speed of 30 m/s towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330 m/s, the frequency of reflected sound as heard by the driver is:
1. 550 Hz
2. 555.5 Hz
3. 720 Hz
4. 500 Hz
| 1. | \(5\) | 2. | \(7\) |
| 3. | \(8\) | 4. | \(3\) |
The wave described by \(y=0.25\sin (10\pi x-2\pi t)\), where \(x \) and \(y\) are in metre and \(t\) in second, is a wave travelling along the:
| 1. | –ve x-direction with frequency \(1\) Hz |
| 2. | +ve x-direction with frequency \(\pi\) Hz and wavelength \(\lambda=0.2\) m |
| 3. | +ve x-direction with frequency \(1\) Hz and wavelength \(\lambda=0.2\) m |
| 4. | –ve x-direction with amplitude \(0.25\) m and wavelength \(\lambda=0.2\) m |
Two sound waves with wavelengths \(5.0~\text{m}\) and \(5.5~\text{m}\), respectively, propagate in gas with a velocity of \(330~\text{m/s}\). How many beats per second can we expect?
1. \(12\)
2. \(0\)
3. \(1\)
4. \(6\)
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