Q.1
A sound wave has frequency 500Hz and velocity 350 m/sec. What is the distance between the two particles having phase difference of 60° [ CPMT 1990]
  • a) 0.7 cm
  • b) 120cm
  • c)70 cm
  • d)120.0 cm
Q.2
Velocity of sound in a gas is proportional to .. [ CPMT 1985]
  • a) Square root of adiabatic elasticity
  • b) Adiabatic elasticity
  • c) Square root of isothermal elasticity
  • d) isothermal elasticity
Q.3
A mass m=100 gm is attached at the end of a light spring which oscillates on a frictionless horizontal table with an amplitude equal to 0.16 m and time period equal to 2 sec. Initially the mass is released from rest at t=0 and displacement of the mass at any time (t) is .. [ PMT 1995]
  • a)x=0.16 cos(πt)
  • b) x=-0.16 cos(πt)
  • c)x=0.16 cos(πt+π)
  • d)x=-0.16cos(πt+π)
Q.4
A traveling wave passes a point of observation. At this point the time interval between successive crests is 0.2 sec ... [ MPPMT 1990]
  • a) Wavelength is 5 metre
  • b) Frequency is 5Hz
  • c)Velocity of propagation is 5 metre/sec
  • d)Wavelength is 0.2 metre
Q.5
A wave equation is given by where y is in cm. Frequency of wave and maximum acceleration will be .. [ Raj.PET 1997]
ch-10_que_no-188_img_no1.png
  • a) 100 HZ, 4.7×10³ cm/s²
  • b) 50 HZ, 7.5×10³ cm/s²
  • c) 25 HZ, 4.7×10³ cm/s²
  • d) 25 HZ, 7.5×10³ cm/s²
Q.6
The particles of medium vibrate about their mean positions whenever a wave travels through that medium. The phase difference between the vibrations of two such particles .. [ SCRA 1994]
  • a)varies with the time
  • b) varies with distance separating them
  • c)varies with time as well as distance
  • d)is always zero
Q.7
An engine is moving on a circular path of radius 100 metres with speed of 20 metres per sec. What will be the frequency observed by an observer standing stationary at the centre of the circular path when the engine blows a whistle of frequency 500Hz
  • a) More than 50 Hz
  • b) Less then 500Hz
  • c) 500 Hz
  • d) No sound
Q.8
At what temperature is the speed of sound in hydrogen will be the same as that in oxygen at 111°C? The ratio of the densities of oxygen and hydrogen is 16:1
  • a) 249°C
  • b) -249°C
  • c)63°C
  • d)-65°C
Q.9
When a tuning fork is made to vibrate, then the vibrations of its prongs
  • a) are in phase
  • b) have a phase difference of π
  • c)have a phase difference of π/2
  • d)have a phase difference of π/4
Q.10
student sees a jet plane flying from east to west when the jet is seen just above his head, the sound of the jet appears to reach him making angle of 60° with the horizontal from east. If the velocity of sound is v, then velocity of jet is
  • a) 2v
  • b) (√3 /2)v
  • c) (2/√3) v
  • d) v/2
Q.11
With increase in temperature, the velocity of sound in liquid, in general
  • a)Increases slightly
  • b) Decreases slightly
  • c)Remains unchanged
  • d)Changes erratically
Q.12
The amplitude of a velocity of particle is given by Vm=Vo / (aω2 - bω+c ) where Vo, a , b, and c are positive. The condition for a single resonant frequency is ...[ CPMT 1998]
  • a) b2 < 4ac
  • b) b2 > 4ac
  • c)b2 < 5ac
  • d)b²=7ac
Q.13
Speed of sound in air is 332 m/s at NTP. The speed of sound in hydrogen at NTP will be [ MNR 1995]
  • a) 5312 m/s
  • b) 2546 m/s
  • c)1328 m/s
  • d)664 m/s
Q.14
Velocity of sound wave in air is 330 metre per sec. For a particular sound in air, a path difference of 40cm is equivalent to phase difference of 1.6π. The frequency of this wave is ...[ CBSE 1980]
  • a) 165 hz
  • b) 150 hz
  • c) 660 hz
  • d) 330 hz
Q.15
Two wires of different densities, are joined at x=An incident wave yi=ai (ωt-k1x) traveling from left to right is partly reflected and partly transmitted at x=If the amplitude of reflected and transmitted waves be ar and ai respectively, then ar / ai is
  • a)
    ch-10_qn-197choice_img_no1.png
  • b)
    ch-10_qn-197choice_img_no2.png
  • c)
    ch-10_qn-197choice_img_no3.png
  • d)
    ch-10_qn-197choice_img_no4.png
Q.16
In a stretched string under tension and fixed at both the ends, the area of cross-section of its wire is halved and tension is doubled. The frequency becomes.
  • a) Twice
  • b) Eight times
  • c)Half
  • d)For times
Q.17
The end correction of a resonance column is 1.0 cm. If the shortest length resonating with a tuning fork is 15.0 cm, the next resonating length is [ MPPMT 1985]
  • a) 31 cm
  • b) 45 cm
  • c)46 cm
  • d)47 cm
Q.18
The fundamental frequency of sonometer wire carrying a block of mass 1 kg and density 1.8 is 260Hz. When the block is completely immersed in a liquid of density 1.2, then what will be its new frequency? [ CPMT 1998]
  • a) 300 Hz
  • b) 150Hz
  • c) 450Hz
  • d) none
Q.19
With a closed organ pipe of length l, the fundamental ton has frequency. [ CPMT 1993]
  • a) ( v/2l) and only even harmonics are present
  • b) ( v/2l) and only odd harmonics are present
  • c) (v/2l) and even as well as odd harmonics are present
  • d) (v/4l) and only odd harmonics are present
Q.20
In an open end organ pipe of length l, if the velocity of sound is v, then the fundamental frequency will be [ CPMT 1990]
  • a) (v/2l) and all harmonics are present
  • b) (v/4l) and all harmonics are present
  • c)(v/2l) and even harmonic are absent
  • d)(v/4l) and even harmonics are absent
Q.21
The frequency of vibration of string can be increased by:
  • a)Increasing the length of the string keeping the tension constant
  • b) Decreasing the density of the string keeping the tension constant
  • c)Increasing the thickness of the string keeping the length constant
  • d)Decreasing the tension of the string keeping the length constant
Q.22
A cylindrical tube, open at both ends has a fundamental frequency 'f' in air. The tube is vertically dipped in water so that half of it is in water, the fundamental frequency of air column is [ BHU 1995]
  • a) f/2
  • b) 3f/4
  • c) f
  • d) 2f
Q.23
The frequency of the fundamental mode of vibration of an organ pipe is 400Hz. When one end of the pipe is closed the fundamental frequency is ..[ EAMCET 1986]
  • a)200 Hz
  • b) 400 Hz
  • c)600Hz
  • d)800 Hz
Q.24
In order to increase the fundamental frequency of string from 100Hz to 400Hz, the tension must be increased by [ EAMCET 19987]
  • a) 2 times
  • b) 4 times
  • c)8 times
  • d)16 times
Q.25
With increase in temperature, the frequency of the sound from an organ pipe.. [ Raj. PET 1996]
  • a)Decreases
  • b) Increases
  • c)Remain unchanged
  • d)Changes erratically
Q.26
The frequencies of the harmonic of the string are ..[ CPMT 1988]
  • a) Unrelated
  • b) Of the same pitch
  • c) In the ratio 1:2:3
  • d) In the ratio 1:3:5
Q.27
A stretched string of length l fixed at both ends can sustain stationary waves of wave length λ given by : [ CPMT 1998,] where n is a whole number
  • a)λ=n2 / 2l
  • b) λ=l2 / 2n
  • c)λ=2l /n
  • d)λ=2ln
Q.28
If oil of density higher than that of water is used in place of water in a resonance tube, its frequency will... [ MNR 1986]
  • a) Increase
  • b) Decrease
  • c)Remain the same
  • d)Depend upon the density of the material of tube
Q.29
The fundamental frequency of a string stretched with weight of 4kg is 256Hz. The weight required to produce its octave is .. [ MPPMT 1988]
  • a)4 kg wt
  • b) 12 kg wt
  • c)16 kg wt
  • d)24 kg wt
Q.30
An open pipe of length 90cm emitting its second overtone is in unison with an open pipe emitting its third overtone. The length of the open pipe will be .. [ EAMCET 1994]
  • a) 1.6 m
  • b) 1.2 m
  • c) 3.2 m
  • d) 2.5 m
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