JEE Questions for Physics Waves Quiz 2 - MCQExams.com

A whistle whose air column is open at both ends, has fundamental frequency of 5100 Hz. If the speed of sound in air is 340 ms -1, the length of the whistle in cm, is
  • 5/3
  • 10/3
  • 5
  • 20/3
A closed pipe is suddenly opened and changed to an open pipe of same length. The fundamental frequency of the resulting open pipe is less than that of 3rd harmonic of the earlier closed pipe by 55 Hz.
Then, the value of fundamental frequency of the closed pipe is
  • 165 Hz
  • 110 Hz
  • 55 Hz
  • 220 Hz
A student is performing the experiment of resonance column. The diameter of the column tube is 4 cm. The frequency of the tuning fork is 512 Hz. The air temperature is 38°C in which the speed of sound is 336 m/s. The zero of the meter scale coincides with the top end of the resonance column tube.
When the first resonance occurs, the reading of the water level in the column is
  • 14.0 cm
  • 15.2 cm
  • 16.4 cm
  • 17.6 cm
A wire under tension vibrates with a fundamental frequency of 600 Hz. If the length of the wire is doubled, the radius is halved and the wire is made to vibrate under one-ninth the tension. Then, the fundamental frequency will became
  • 400 Hz
  • 600 Hz
  • 300 Hz
  • 200 Hz
Tube A has both ends open while tube B has one end closed. Otherwise they are identical. Their fundamental frequencies are in the ratio
  • 4 : 1
  • 2 : 1
  • 1 : 4
  • 1 : 2
  • 2 : 3
A hollow pipe of length 0.8 m is closed at one end. At its open end a 0.5 m long uniform string is vibrating in its second harmonic and it resonates with the fundamental frequency of the pipe. If the tension in the wire is 50 N and the speed of sound is 320 ms -1, the mass of the string is
  • 5 g
  • 10 g
  • 20 g
  • 40 g
In a resonance tube, using a tuning fork of frequency 325 Hz, two successive resonance lengths are observed as 25.4 cm and 77.4 cm respectively. The velocity of sound in air is
  • 338 ms-1
  • 328 ms-1
  • 330 ms-1
  • 320 ms-1
In the fundamental mode, time taken by the wave to reach the closed end of the air filled pipe is 0.01 s. The fundamental frequency is
  • 25
  • 12.5
  • 20
  • 15
A 20 cm long string, having a mass of 1.0 g, is fixed at both the ends. The tension in the string is 0.5 N. The string is set into vibration using an external vibrator of frequency 100 Hz. Find the separation (in cm) between the successive nodes on the string.
  • 5
  • 6
  • 2
  • 3/2
In a stationary wave represented by, y = 2a cos kx sin ωt, the intensity at a certain point is maximum, when
  • cos kx is maximum
  • cos kx is minimum
  • sin ωt is maximum
  • sin ωt is minimum
A pulse or a wave train travels along a stretched string and reaches the fixed end of the string. It will be reflected back with
  • the same phase as the incident pulse but with velocity reversed
  • a phase change of 180° with no reversal of velocity
  • the same phase as the incident pulse with no reversal of velocity
  • a phase change of 180° with velocity reversed
The length of an elastic string is, a metre when the longitudinal tension is 4 N and b metre when the longitudinal tension is 5 N. The length of the string in metre when longitudinal tension is 9 N, is
  • a – b
  • 5b – 4a

  • Physics-Waves-96009.png
  • 4a – 3b
In a resonance pipe, the first and second resonances are obtained at depths 22.7 cm and 70.2 cm respectively. What will be the end correction?
  • 1.05 cm
  • 115.5 cm
  • 92.5 cm
  • 113.5 cm
Fundamental frequency of pipe is 100 Hz and other two frequencies are 300 Hz and 500 Hz, then
  • pipe is open at both the ends
  • pipe is closed at both the ends
  • one end is open and another end is closed
  • None of the above
If you set up the seven overtone on a string fixed at both ends, how many nodes and anti nodes are set up in it?
  • 6, 5
  • 5, 4
  • 4, 3
  • 3,2
On which principle does sonometer works?
  • Hooke's law
  • Elasticity
  • Resonance
  • Newton's law
If in a resonance tube, oil of density higher than that water is used, then at the resonance frequency would
  • increase
  • decrease
  • slightly increase
  • remains same
A string vibrates with a frequency of 200 Hz. When its length is doubled and tension is altered, it begins to vibrate with a frequency of 300 Hz. The ratio of the new tension to the original tension is
  • 9 : 1
  • 1 : 9
  • 3 : 1
  • 1 : 3
A sonometer wire 100 cm long has a fundamental frequency of 330 Hz. The velocity of propagation of transverse waves on the wire is
  • 330 ms-1
  • 660 ms-1
  • 990 ms-1
  • 115 ms-1
  • 550 ms-1
A hollow cylinder with both sides open generates a frequency v in air. When the cylinder vertically immersed into water by half its length, the frequency will be
  • v
  • 2v
  • v/2
  • v/4
Two stretched strings have lengths l and 2l while tensions are T and 4T respectively. If they are made of same material, the ratio of their frequencies is
  • 2 : 1
  • 1 : 2
  • 1 : 1
  • 1 : 4
The frequency of the fundamental note in a wire stretched under tension T is v. If the tension is increased to 25 T. then the frequency of the fundamental note will be
  • 25v
  • 5v
  • 10v
  • v
The frequency of fundamental note in an organ pipe is 240 Hz. On blowing air, frequencies 720 Hz and 1200 Hz are heard. This indicates that organ pipe is
  • a pipe closed at one end
  • a pipe open at both ends
  • closed at both ends
  • having holes like flute
In the experiment to determine the speed of sound using a resonance column
  • prongs of the tuning fork are kept in a vertical plane
  • prongs of the tuning fork are kept in a horizontal plane
  • in one of the two resonances observed, the length of the resonating air-column is close to the wavelength of sound in air
  • in one of the two resonances observed, the length of the resonating air-column is close to half of the wavelength of sound in air
A metal wire of linear mass density of 9.8 gm-1 is stretched with a tension of 10 kg-wt between two rigid supports 1 m apart. The wire passes at its middle point between the poles of a permanent magnet and it vibrates in resonance when carrying an alternating current of frequency v. The frequency v of the alternating sources is
  • 50 Hz
  • 100 Hz
  • 200 Hz
  • 25 Hz

Physics-Waves-96010.png
  • 260 Hz
  • 130 Hz
  • 390 Hz
  • 520 Hz
An open organ pipe of length l vibrates in its fundamental mode. The pressure variation is maximum
  • at the two ends
  • 2)
    Physics-Waves-96011.png

  • Physics-Waves-96012.png

  • Physics-Waves-96013.png
A closed organ pipe and an open organ pipe are tuned to the same fundamental frequency. The ratio of their lengths is
  • 1 : 1
  • 2 : 1
  • 1 : 4
  • 1 : 2
A string is stretched between fixed points separated by 75 cm. It is observed to have resonant frequency of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is
  • 105 Hz
  • 1.05 Hz
  • 1050 Hz
  • 10.5 Hz
A note has a frequency 128 Hz. The frequency of a note two octaves higher than it is
  • 256 Hz
  • 64 Hz
  • 32 Hz
  • 512 Hz
Two vibrating strings of the same material but lengths L and 2L have radii 2r and r respectively. They are stretched under the same tension. Both the strings vibrate in their fundamental modes, the one of length L with frequency v2. The ratio v1 /v2 is
  • 2 : 1
  • 4 : 1
  • 8 : 1
  • 1 : 1
The second overtone of an open pipe is in resonance with the first overtone of a closed pipe of length 2 m. Length of the open pipe is
  • 4 m
  • 2 m
  • 8 m
  • 1 m
Two wires are fixed in a sonometer. Their tensions are in the ratio 8 : 1. The lengths are in the ratio 36 : 35. The diameters are in the ratio 4 : 1. Densities of the materials are in the ratio 1 : 2. If the higher frequency in the setting is 360 Hz, the beat frequency when the two wires are sounded together, is
  • 8
  • 5
  • 10
  • 6
If v is the speed of sound in air, then the shortest length of the closed pipe which resonates to a frequency v, is

  • Physics-Waves-96014.png
  • 2)
    Physics-Waves-96015.png

  • Physics-Waves-96016.png

  • Physics-Waves-96017.png
In 1 m long open pipe, what is the harmonic of resonance obtained with a tuning fork of frequency 480 Hz?
  • First
  • Second
  • Third
  • Fourth
A string of length 2 m is fixed at both ends. If this string vibrates in its fourth normal mode with a frequency of 500 Hz, then the waves would travel on it with a velocity of
  • 125 ms-1
  • 250 ms-1
  • 500 ms-1
  • 1000 ms-1
The fundamental frequency of a sonometer wire is v. If its radius is doubled and its tension becomes half, the material of the wire remains same, the new fundamental frequency will be
  • v
  • 2)
    Physics-Waves-96019.png

  • Physics-Waves-96020.png

  • Physics-Waves-96021.png
In open organ pipe, if fundamental frequency is v, then the other frequencies are
  • v, 2v, 3v, 4v
  • v, 3v, 5v
  • v, 2v, 4v, 8v
  • None of these
An organ pipe, open at both ends produces 5 beats/s, when vibrated with a source of frequency 200 Hz. The second of the same pipe produces 10 beats/s with a source of frequency 420 Hz. The frequency of source is
  • 195 Hz
  • 205 Hz
  • 190 Hz
  • 210 Hz
An organ pipe open at one end is vibrating in first overtone and is in resonance with another pipe open at both ends and vibrating in third harmonic. The ratio of length of two pipes is
  • 1 : 2
  • 4 : 1
  • 8 : 3
  • 3 : 8
An open pipe is suddenly closed at one end with the result that the frequency of third harmonic of the closed pipe is found to be higher by 100Hz than the fundamental frequency of the open pipe. The fundamental frequency of the open pipe is
  • 200 Hz
  • 300 Hz
  • 240 Hz
  • 480 Hz
A car is moving with a speed of 72 km–h -1 towards a roadside source that emits found at a frequency of 850 Hz. The car driver listens to the sound while approaching the source and again while moving away from the source after crossing it. If the velocity of sound is 340 ms -1 , the difference of the two frequencies, the driver hears is
  • 50 Hz
  • 85 Hz
  • 100 Hz
  • 150 Hz
A horizontal stretched string, fixed at two ends, is vibrating in its fifth harmonic according to the equation, y(x, t ) = (0.01 m) [sin (62.8 m-1 ) x cos (628 s-1 )t]. Assuming rc = 3.14, the correct statement(s) is (are)
  • the number of nodes is 5
  • the length of the string is 0.25 m
  • the maximum displacement of the mid-point of the string from its equilibrium position is 0.01 m
  • the fundamental frequency is 100 Hz
A man standing between two cliffs, claps his hands and starts hearing a series of echoes at intervals of one second. If the speed of sound in air is 340 ms -1, the distance between the cliffs is
  • 680 m
  • 1700 m
  • 340 m
  • 1620 m
A whistle of frequency 500 Hz tied to the end of a string of length of 1.2 m revolves at 400 rev/min. A listener standing some distance away in the plane of rotation of whistle frequencies in the rays (speed of sound = 340 ms -1).
  • 436 to 586
  • 426 to 574
  • 436 to574
  • 436 to 584
A racing car moving towards a cliff, sounds its horn. The driver observes that the sound reflected from the cliff has a pitch one octave higher than the actual sound of the horn. If v is the velocity of sound, then the velocity of the car is
  • v/2
  • v/√2
  • v/4
  • v/3
A train is approaching with velocity 25 ms -1 towards a pedestrain standing on the track, frequency of horn of train is 1 kHz. Frequency heard by the pedestrain is (take, v = 350 ms -1 )
  • 1077 Hz
  • 1167 Hz
  • 985 Hz
  • 954 Hz
The change in frequency due to Doppler's effect does not depends on
  • the speed of the source
  • the speed of the observer
  • the frequency of the source
  • separation between the source and the observer
A train approaching a railway platform with a speed of 20 ms -1 starts blowing the whistle, speed of sound in air is 340 ms -1. If the frequency of the emitted sound from the whistle is 640 Hz, the frequency of sound to a person standing on the platform will appear to be
  • 600 Hz
  • 640 Hz
  • 680 Hz
  • 720 Hz
A police car with a siren of frequency 8 kHz is moving with uniform velocity 36 km/h towards a tall building which reflects the sound waves. The speed of sound in air is 320 m/s. The frequency of the siren heard by the car driver is
  • 8.5 kHz
  • 8.25 kHz
  • 7.25 kHz
  • 7.5 kHz
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