JEE Questions for Physics Waves Quiz 11 - MCQExams.com

Two strings X and Y of a sitar produce a beat frequency 4 Hz. When the tension of the string Y is slightly increased the beat frequency is found to be 2 Hz. If the frequency of X is 300 Hz, then the original frequency of Y was
  • 296 Hz
  • 298 Hz
  • 302 Hz
  • 304 Hz
The wavelengths of two waves are 50 and 51 cm respectively. If the temperature of the room is 20°C, then what will be the number of beats produced per second by these waves, when the speed of sound at 0°C is 332 m/sec?
  • 14
  • 10
  • 24
  • None of these
Two sound waves of slightly different frequencies propagating in the same direction produce beats due to
  • Interference
  • Diffraction
  • Polarization
  • Refraction
It is possible to hear beats from the two vibrating sources of frequency
  • 100 Hz and 150 Hz
  • 20 Hz and 25 Hz
  • 400 Hz and 500 Hz
  • 1000 Hz and 1500 Hz
The wavelength of a wave is 99 cm and that of other is 100 cm. Speed of sound is 396 m/s. The number of beats heard is
  • 4
  • 5
  • 1
  • 8
A tuning fork arrangement (pair) produces 4 beats/sec with one fork of frequency 288 cps. A little wax is placed on the unknown fork and it then produces 2 beats/sec. The frequency of the unknown fork is
  • 286 cps
  • 292 cps
  • 294 cps
  • 288 cps
When temperature increases, the frequency of a tuning fork
  • Increases
  • Decreases
  • Remains same
  • Increases or decreases depending on the material
How many times more intense is a 60 dB sound than a 30 dB sound?
  • 100
  • 4
  • 1000
  • 2
Two sources produce sound waves of equal amplitudes and travelling along the same direction producing 18 beats in 3 seconds. If one source has a frequency of 341 Hz, the frequency of the other source may be
  • 329 or 353 Hz
  • 335 or 347 Hz
  • 338 or 344 Hz
  • 332 or 350 Hz
The distance between the nearest node and antinode in a stationary wave is
  • λ
  • λ /2
  • λ /4
  • 2λ
In stationary wave
  • Strain is maximum at nodes
  • Strain is maximum at antinodes
  • Strain is minimum at nodes
  • Amplitude is zero at all the points
The phase difference between the two particles situated on both the sides of a node is
  • 0°
  • 90°
  • 180°
  • 360°
Two travelling waves y1= A sin [k(x — ct)] and y2 = A sin [k(x + a)] are superimposed on string. The distance between adjacent nodes is
  • ct / π
  • ct / 2π
  • π / 2k
  • π / k
Consider the three waves z1, z2 and z3 as
z1 = A sin (kx – ωt), z2 = A sin (kx + ωt)
and z3 = A sin (ky – ωt).
Which of the following represents a standing wave ?
  • z1 + z2
  • z2 + z3
  • z3 + z1
  • z1 + z2 + z3

Physics-Waves-96607.png
  • Transverse progressive wave
  • Longitudinal progressive wave
  • Longitudinal stationary wave
  • Transverse stationary wave
At nodes in stationary waves
  • Change in pressure and density are maximum
  • Change in pressure and density are minimum
  • Strain is zero
  • Energy is minimum
In a stationary wave, all particles are
  • At rest at the same time twice in every period of oscillation
  • At rest at the same time only once in every period of oscillation
  • Never at rest at the same time
  • Never at rest at all
At a certain instant a stationary transverse wave is found to have maximum kinetic energy. The appearance of string at that instant is
  • Sinusoidal shape with amplitude A/3
  • Sinusoidal shape with amplitude A/2
  • Sinusoidal shape with amplitude A
  • Straight line
The equation y = 0.15 sin 5x cos 300t, describes a stationary wave. The wavelength of the stationary wave is
  • Zero
  • 1.256 metres
  • 2.512 metres
  • 0.628 metre
In stationary waves, antinodes are the points where there is
  • Minimum displacement and minimum pressure change
  • Minimum displacement and maximum pressure change
  • Maximum displacement and maximum pressure change
  • Maximum displacement and minimum pressure change
In stationary waves all particles between two nodes pass through the mean position
  • At different times with different velocities
  • At different times with the same velocity
  • At the same time with equal velocity
  • At the same time with different velocities
A wave of wavelength 2m is reflected from a surface. If a node is formed at 3m from the surface, then at what distance from the surface another node will be formed
  • 1 m
  • 2 m
  • 3 m
  • 4 m
In stationary waves, distance between a node and its nearest antinode is 20 cm. The phase difference between two particles having a separation of 60 cm will be
  • Zero
  • π / 2
  • π
  • 3π /2
Stationary waves of frequency 300 Hz are formed in a medium in which the velocity of sound is 1200 metre/sec. The distance between a node and the neighboring antinodes is
  • 1 m
  • 2 m
  • 3 m
  • 4 m
Which two of the given transverse waves will give stationary waves when get superimposed
z1 = a cos (kx – ωt) ... (A)
z2 = a cos (kx + ωt) … (B)
z3 = a cos (ky – ωt) … (C)
  • A and B
  • A and C
  • B and C
  • Any two
Two waves are approaching each other with a velocity of 20 m/s and frequency n. The distance between two consecutive nodes is

  • Physics-Waves-96612.png
  • 2)
    Physics-Waves-96613.png

  • Physics-Waves-96614.png

  • Physics-Waves-96615.png
Energy is not carried by which of the following waves?
  • Stationary
  • Progressive
  • Transverse
  • Electromagnetic

Physics-Waves-96617.png
  • 3 cm
  • 4.5 cm
  • 6 cm
  • 1.5 cm
Two sinusoidal waves with same wavelengths and amplitudes travel in opposite directions along a string with a speed 10 ms–1. If the minimum time interval between two instants when the string is flat is 0.5 s, the wavelength of the waves is
  • 25 m
  • 20 m
  • 15 m
  • 10 m
In a stationary wave all the particles
  • On either side of a node vibrate in same phase
  • In the region between two nodes vibrate in same phase
  • In the region between two antinodes vibrate in same phase
  • Of the medium vibrate in same phase
When a stationary wave is formed then its frequency is
  • Same as that of the individual waves
  • Twice that of the individual waves
  • Half that of the individual waves
  • None of the above
A string fixed at both the ends is vibrating in two segments. The wavelength of the corresponding wave is

  • Physics-Waves-96621.png
  • 2)
    Physics-Waves-96622.png

  • Physics-Waves-96623.png

  • Physics-Waves-96624.png
A 1 cm long string vibrates with fundamental frequency of 256 Hz. If the length is reduced to 1/4 cm keeping the tension unaltered, the new fundamental frequency will be
  • 64
  • 256
  • 512
  • 1024
The velocity of waves in a string fixed at both ends is 2 m/s. The string forms standing waves with nodes 5.0 cm apart. The frequency of vibration of the string in Hz is
  • 40
  • 30
  • 20
  • 10
Which of the following is the example of transverse wave?
  • Sound waves
  • Compressional waves in a spring
  • Vibration of string
  • All of the above
Two similar sonometer wires given fundamental frequencies of 500 Hz. These have same tensions. By what amount the tension be increased in one wire so that the two wires produce 5 beats/sec?
  • 1%
  • 2%
  • 3%
  • 4%
If the tension of sonometer\'s wire increases four times then the fundamental frequency of the wire will increase by
  • 2 times
  • 4 times
  • 1/2 times
  • None of these
Four wires of identical length, diameters and of the same material are stretched on a sonometre wire. If the ratio of their tensions is 1 : 4 : 9 : 16 then the ratio of their fundamental frequencies are
  • 16 : 9 : 4 : 1
  • 4 : 3 : 2 : 1
  • 1 : 4 : 2 : 16
  • 1 : 2 : 3 : 4
A tuning fork vibrating with a sonometer having 20 cm wire produces 5 beats per second. The beat frequency does not change if the length of the wire is changed to 21 cm. The frequency of the tuning fork (in Hertz) must be
  • 200
  • 210
  • 205
  • 215
If you set up the seventh harmonic on a string fixed at both ends, how many nodes and antinodes are set up in it?
  • 8, 7
  • 7, 7
  • 8, 9
  • 9, 8
If you set up the ninth harmonic on a string fixed at both ends, its frequency compared to the seventh harmonic
  • Higher
  • Lower
  • Equal
  • None of these
Frequency of a sonometer wire is n. Now its tension is increased 4 times and its length is doubled then new frequency will be
  • n/2
  • 4n
  • 2n
  • n
A device used for investigating the vibration of a fixed string or wire is
  • Sonometer
  • Barometer
  • Hydrometer
  • None of these
To increase the frequency from 100 Hz to 400 Hz the tension in the string has to be changed by
  • 4 times
  • 16 times
  • 20 times
  • None of these
A second harmonic has to be generated in a string of length l stretched between two rigid supports. The point where the string has to be plucked and touched are

  • Physics-Waves-96635.png
  • 2)
    Physics-Waves-96636.png

  • Physics-Waves-96637.png

  • Physics-Waves-96638.png
Transverse waves of same frequency are generated in two steel wires A and B. The diameter of A is twice of B and the tension in A is half that in B. The ratio of velocities of wave in A and B is

  • Physics-Waves-96640.png
  • 2)
    Physics-Waves-96641.png
  • 1 : 2

  • Physics-Waves-96642.png
The musical interval between two tones of frequencies 320 Hz and 240 Hz is
  • 80
  • 2)
    Physics-Waves-96803.png
  • 560
  • 320 × 240
A sonometer wire resonates with a given tuning fork forming standing waves with five antinodes between the two bridges when a mass of 9 kg is suspended from the wire. When this mass is replaced by a mass M, the wire resonates with the same tuning fork forming three antinodes for the same positions of the bridges. The value of M is
  • 25 kg
  • 5 kg
  • 12.5 kg
  • 1/25 kg
The tension of a stretched string is increased by 69%. In order to keep its frequency of vibration constant, its length must be increased by
  • 20%
  • 30%
  • √69%
  • 69%
The length of a sonometer wire tuned to a frequency of 250 Hz is 0.60 metre. The frequency of tuning fork with which the vibrating wire will be in tune when the length is made 0.40 metre is
  • 250 Hz
  • 375 Hz
  • 256 Hz
  • 384 Hz
0:0:1


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