A source of sound with frequency 256 Hz is moving with a velocity v towards a wall and an observer is stationary between the source and the wall. When the observer is between source and the wall, he finds that the frequency of the waves received directly from the source is x and the frequency of the waves received after reflection from the wall is y; then -
A car moving at 20 m/s with its horn blowing (n = 1200 Hz) is chasing another car going at 15 m/s. What is the apparent frequency of the horn as heard by the driver being chased ? (Take the speed of the sound to be 340 m/s )
Two tuning forks A and B are in unison with strings of length 0.96 m and 0.97 m respectively produces 2 beats per half second. The frequency of A and B are in (Hz) –
The absolute temperature of air in a region linearly increases from 00C to 8190C in a space of width 'd'. Time taken by sound wave to travel through this space is: [Velocity of sound at 00C is v0]
A tuning fork and an air column in resonance tube whose temperature is 51°C produces 4 beats in 1 second when sounded together. When the temperature of the air column decreases, the number of beats per second decreases. When the temperature remains 16°C, only 1 beat per second is produced. Then the frequency of the tuning fork is -
Two tuning forks when sounded together produced 4 beats/sec. The frequecy of one fork is 256. The number of beats heard increases when the fork is loaded with wax. The frequency of the other fork is-
A tuning fork of frequency 480 Hz produces 10 beats per second when sounded with a vibrating sonometer string. What must have been the frequency of the string if a slight increase in tension produces lesser beats per second than before-
When sound wave is refracted from air to water, which of the following will remain unchanged?
The frequency of a man’s voice is 300 Hz and its wavelength is 1 meter. If the wavelength of a child’s voice is 1.5 m, then the frequency of the child’s voice is:
The ratio of speed of sound in a monoatomic gas to that in water vapours at any temperature is. (when molecular weight of gas is 40 gm/mol and for water vapours is 18 gm/mol)
Under similar conditions of temperature and pressure, In which of the following gases the velocity of sound will be largest.
A sound of intensity I is greater by 3.0103 dB from another sound of intensity 10 nW cm–2. The absolute value of intensity of sound level I in Wm–2 is
For a sound source of intensity I W/m2, corresponding sound level is B0 If the intensity is increased to 4I, new sound level becomes approximately :
The sound intensity is 0.008 W/m2 at a distance of 10 m from an isotropic point source of sound. The power of the source is approximately
What happens when a sound wave interferes with another wave of same frequency and constant phase difference ?
Sound waves from a tuning fork F reach a point P by two separate routes FAP and FBP (when FBP is greater than FAP by 12 cm there is silence at P). If the difference is 24 cm the sound becomes maximum at P but at 36 cm there is silence again and so on. If velocity of sound in air is 330 ms–1, the least frequency of tuning fork is :
A person is talking in a small room and the sound intensity level is 60 dB everywhere within the room. If there are eight people talking simultaneously in the room, what is the sound intensity level ?
When a sound wave is reflected from a wall, the phase difference between the reflected and incident pressure wave is:
The maximum variation of pressure in an open organ pipe of length vibrating in fundamental mode is at.
The fundamental frequency of a closed organ pipe is same as the first overtone frequency of an open pipe. If the length of open pipe is 50 cm, the length of closed pipe is
The second overtone of an open pipe A and a closed pipe B have the same frequencies. The ratio of fundamental frequency of A to the fundamental frequency of B is:
A resonance tube is resonated with tuning fork of frequency 256 Hz. If the length of first and second resonating air columns are 32 cm and 100 cm, then end correction will be
