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.
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
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
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
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 \(10\) |