Two sound waves with wavelengths 5.0 m and 5.5 m, respectively, propagate in gas with a velocity of 330 m/s. How many beats per second can we expect?
1. 12
2. 0
3. 1
4. 6
A transverse wave propagating along the x-axis is represented by:
\(y=(x,t)=8.0\mathrm{sin}(0.5\pi x-4\pi t-\frac{\pi}{4})\) where \(x\) is in meters and \(t\) in seconds. The speed of the wave is:
1. \(4\pi\) m/s
2. \(0.5\) m/s
3. \(\frac{\pi}{4}\) m/s
4. \(8\) m/s
The time of reverberation of a room \(A\) is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double those of room A?
1. 2
2. 4
3.
4. 1
Which one of the following statements is true?
1. | Both light and sound waves in the air are transverse. |
2. | The sound waves in the air are longitudinal while the light waves are transverse. |
3. | Both light and sound waves in the air are longitudinal. |
4. | Both light and sound waves can travel in a vacuum. |
Statement–1 : In the case of a stationary wave,
a person hear a loud sound at the pressure nodes
as compared to the antinodes.
and
Statement–2 : In a stationary wave all the
particles of the medium vibrate in phase.
1. Statement-1 is True, Statement-2 is True,
Statement-2 is a correct explanation for
statement-1
2. Statement-1 is True, Statement-2 is True,
Statement-2 is NOT a correct explanation
for Statement-1
3. Statement-1 is True, Statement-2 is False
4. Statement-1 is False, Statement-2 is True
A : The propagation of sound in air should be an isothermal process.
R : As air is bad conductor of heat, its temperature does not change by compression or expansion.
Each of the two strings of lengths 51.6 cm and 49.1 cm is tensioned separately by 20 N of force. The mass per unit length of both strings is the same and equals 1 g/m. When both the strings vibrate simultaneously, the number of beats is:
1. | 5 | 2. | 7 |
3. | 8 | 4. | 3 |
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
A wave in a string has an amplitude of 2 cm. The wave travels in the positive direction of the x-axis with a speed of 128 m/s and it is noted that 5 complete waves fit in the 4 m length of the string. The equation describing the wave is:
1. | y = (0.02)m sin(7.85x+1005t) |
2. | y = (0.02)m sin(15.7x -2010t) |
3. | y = (0.02)m sin(15.7x+2010t) |
4. | y = (0.02)m sin(7.85x -1005t) |
Sound waves travel at \(350\) m/s through warm air and at \(3500\) m/s through brass. The wavelength of a \(700\) Hz acoustic wave as it enters brass from warm air:
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 \(10\) |