How many degrees of freedom the gas molecules have if, under \(\text{STP}\), the gas density \(\rho = 1.3~\text{kg/m}^3\) and the velocity of sound propagation in it is \(330~\text{ms}^{-1}\)?
1. \(3\)
2. \(5\)
3. \(7\)
4. \(8\)
A plane progressive wave cannot be represented by
1.
2.
3.
4.
When a wave is reflected from a denser medium the change in phase is :
1. 0
2.
3.
4.
A source of sound moves away with the velocity of sound from a stationary observer. The frequency of the sound heard by the observer:
1. remains the same
2. is doubled
3. is halved
4. becomes infinity
The equation of a wave pulse travelling along x-axis is given by , x and y are in meters and t is in seconds. The amplitude of the wave pulse is
1. 5 m
2. 20 m
3. 15 m
4. 30 m
Eleven tuning forks are arranged in increasing order of frequency in such a way that any two consecutive tuning forks produce 4 beats per second. The highest frequency is twice that of the lowest. The highest and the lowest frequencies (in Hz) are, respectively:
1. | 100 and 50 | 2. | 44 and 22 |
3. | 80 and 40 | 4. | 72 and 30 |
When a sound wave travels from one medium to another, the quantity that remains unchanged is :
1. speed
2. amplitude
3. frequency
4. wavelength
If a sound source of frequency n approaches an observer with velocity v/4 and the observer approaches the source with velocity v/5, then the apparent frequency heard will be-
1. (5/8)n
2. (8/5)n
3. (7/5)n
4. (5/7)n
The third overtone of a closed pipe is observed to be in unison with the second overtone of an open pipe. The ratio of the lengths of the pipes is:
1. | 3/2 | 2. | 5/3 |
3. | 7/4 | 4. | 7/6 |
The two nearest harmonics of a tube close at one end and open at the other end are 220Hz and 260Hz. What is the fundamental frequency of the system?
1. | 10Hz | 2. | 20Hz |
3. | 30Hz | 4. | 40Hz |