JEE Questions for Physics Waves Quiz 3 - MCQExams.com

A car sounding its horn at 480 Hz moves towards a high wall at a speed of 20 ms-1. If the speed of sound is 340 ms -1, the frequency of the reflected sound heard by the girl sitting in the car will be closest to
  • 540 hz
  • 524 Hz
  • 568 Hz
  • 480 Hz
An observer is approaching a stationary source with a velocity 1/4 th of the velocity of sound. Then the ratio of the apparent frequency to actual frequency of source is
  • 4 : 5
  • 5 : 4
  • 2 : 3
  • 3 : 2
  • 2 : 5
Two trains, each moving with a velocity of 30 ms -1, cross each other. One of the trains gives a whistle whose frequency is 600 Hz. If the speed of sound is 330 ms -1, the apparent frequency for passengers sitting in the other train before crossing would be
  • 600 Hz
  • 630 Hz
  • 920 Hz
  • 720 Hz
A car is moving with a speed of 72 kmh -1 towards a hill. Car blows horn at a distance of 1800 m from the hill. If echo is heard after 10 s, the speed of sound (in ms -1) is
  • 300
  • 320
  • 340
  • 360
An observer moves towards a stationary source of sound with a velocity one-fifth of the velocity of sound. What is the percentage increases in the apparent frequency?
  • zero
  • 0.5%
  • 5%
  • 20%
Doppler phenomena is related with
  • pitch (frequency)
  • loudness
  • quality
  • reflection
Radar waves are sent towards a moving aeroplane and the reflected waves are received. When the aeroplane is moving towards the radar, the wavelength of the wave
  • decreases
  • increases
  • ramains the same
  • sometimes increases or decreases
When both the listener and source are moving towards each other, then which of the following is true regarding frequency and wavelength of wave observed by the observer?
  • More frequency, less wavelength
  • More frequency, more wavelength
  • Less frequency, less wavelength
  • More frequency, constant wavelength
A man is standing on the platform and one train is approaching and another train is going away with speed of 4 ms -1, frequency of sound produced by train is 240 Hz. What will be the number of beats heard by him per second?
  • 12
  • Zero
  • 6
  • 3
The disc of a siren containing 60 holes rotates at a constant speed of 360 rpm. The emitted sound is in unison with a tuning fork of frequency
  • 10 Hz
  • 360 Hz
  • 216 Hz
  • 60 Hz
A motor car is approaching towards a crossing with a velocity of 72 kmh -1. The frequency of sound of its horn as heard by a policeman standing on the crossing is 260 Hz. The frequency of horn is
  • 200 Hz
  • 244 Hz
  • 150 Hz
  • 80 Hz
A stationary point source of sound emits sound uniformly in all directions in a non-absorbing medium. Two points P and Q are at a distance of 4 m and 9 m respectively from the source.
The ratio of amplitudes of the waves at P and Q is

  • Physics-Waves-96027.png
  • 2)
    Physics-Waves-96028.png

  • Physics-Waves-96029.png

  • Physics-Waves-96030.png
How many times more intense is a 60 dB sound than a dB sound?
  • 1000
  • 2
  • 100
  • 4
A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of
  • 1000
  • 10000
  • 10
  • 100
A transverse wave is moving in a wire of length of 15 cm long and due to reflection, four anti-nodes are formed. Velocity of wave is 2 m/s, then its frequency is
  • 20 Hz
  • 30 Hz
  • 40 Hz
  • 45 Hz
The speed of sound in gas of density p at a pressure p is proportional to

  • Physics-Waves-96034.png
  • 2)
    Physics-Waves-96035.png

  • Physics-Waves-96036.png

  • Physics-Waves-96037.png

  • Physics-Waves-96038.png
The ratio of the velocity of sound in hydrogen (γ = 7/to that in helium (γ = 5/at the same temperature is

  • Physics-Waves-96040.png
  • 2)
    Physics-Waves-96041.png

  • Physics-Waves-96042.png

  • Physics-Waves-96043.png

Physics-Waves-96044.png
  • 1/2
  • 1/4
  • 1/8
  • 1/16

Physics-Waves-96045.png

  • Physics-Waves-96046.png
  • 2)
    Physics-Waves-96047.png

  • Physics-Waves-96048.png

  • Physics-Waves-96049.png

Physics-Waves-96051.png

  • Physics-Waves-96052.png
  • 2)
    Physics-Waves-96053.png

  • Physics-Waves-96054.png

  • Physics-Waves-96055.png
The equation of a simple harmonic progressive wave is given by, y=A sin(100πt – 3x). Find the distance between 2 particles having a phase difference of π/3

  • Physics-Waves-96057.png
  • 2)
    Physics-Waves-96058.png

  • Physics-Waves-96059.png

  • Physics-Waves-96060.png

Physics-Waves-96061.png
  • 8 m
  • 10 m
  • 5 m
  • 32 m
When a wave travels in a medium, the particle displacement is given by equation, y = a sin 2π (bt – cx), where a, b and c are constants. The maximum particle velocity will be twice the wave velocity if

  • Physics-Waves-96062.png
  • c= πa
  • b = ac

  • Physics-Waves-96063.png
  • a = bc
In a sinusoidal wave, the time required for a particular point to move from maximum displacement to zero displacement is 0.14 s. The frequency of the wave is
  • 0.42 Hz
  • 2.75 Hz
  • 1.79 Hz
  • 0.56 Hz
  • 3.5 Hz

Physics-Waves-96064.png

  • Physics-Waves-96065.png
  • 2)
    Physics-Waves-96066.png

  • Physics-Waves-96067.png

  • Physics-Waves-96068.png
A wave travelling along the X-axis is described by the equation, y (x, t) = 0.005 cos (αx – βt). If the wavelength and the time period of the wave are 0.08 m and 2.0 s respectively, then a and 13 in appropriate units are
  • α = 25π, β = π
  • 2)
    Physics-Waves-96069.png

  • Physics-Waves-96070.png

  • Physics-Waves-96071.png
When a sound wave of wavelength λ. is propagating in a medium, the maximum velocity of the particle is equal to the wave velocity. The amplitude of wave is

  • Physics-Waves-96073.png
  • 2)
    Physics-Waves-96074.png

  • Physics-Waves-96075.png

  • Physics-Waves-96076.png
A wave equation is y = 0.1 sin [100πt – kx] and wave velocity is 100 ms -1 , its wave number is equal to
  • 1 m-1
  • 2 m-1
  • π m-1
  • 2π m-1
The equation of a progressive wave can be given by y =15sin (660πt – 0.02πx). The frequency of the wave is
  • 330 Hz
  • 342 Hz
  • 365 Hz
  • 660 Hz
A wave travelling along a string is described by the equation, y = a sin (ωt – kx). The maximum particle velocity is

  • Physics-Waves-96078.png
  • 2)
    Physics-Waves-96079.png

  • Physics-Waves-96080.png

  • Physics-Waves-96081.png

Physics-Waves-96082.png

  • Physics-Waves-96083.png
  • 2)
    Physics-Waves-96084.png
  • zero

  • Physics-Waves-96085.png

Physics-Waves-96086.png

  • Physics-Waves-96087.png
  • 2)
    Physics-Waves-96088.png

  • Physics-Waves-96089.png

  • Physics-Waves-96090.png

  • Physics-Waves-96091.png
Two points on a travelling wave having frequency 500 Hz and velocity 300 ms -1 are 60° out of phase, then the minimum distance between the two points is
  • 0.2
  • 0.1
  • 0.5
  • 0.4

Physics-Waves-96093.png
  • 2000 ms-1
  • 5 ms-1
  • 20 ms-1
  • 5π ms-1
If the equation of transverse wave is y = 2sin (kx – 2t ), then the maximum particle velocity is
  • 4 unit
  • 2 unit
  • zero
  • 6 unit

Physics-Waves-96095.png
  • its wavelength is 0.2 units
  • it is travelling in the positive x–direction
  • wave velocity is 1.5 units
  • time period of SHM is 1 s
Two waves are represent by, y1 = A sin (kx – ωt) and y2 = A cos (kx – ωt).
The amplitude of resultant wave is
  • 4A
  • 2A
  • √2 A
  • A

Physics-Waves-96097.png
  • 2
  • 3
  • 1
  • 4
Two periodic waves of intensities I1 and I2 pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is
  • I1 + I2
  • 2)
    Physics-Waves-96098.png

  • Physics-Waves-96099.png
  • 2(I1 + I
A wave has velocity v in medium P and velocity 2v in medium Q. If the wave is incident in medium Pat an angle of 30°, then the angle of refraction will be
  • 30°
  • 45°
  • 60°
  • 90°
Sound waves of frequency v = 600 Hz fall normally on a perfectly reflecting wall. The shortest distance from the wall at which all particles will have maximum amplitude of vibration will be (speed of sound – 300 ms-1 )

  • Physics-Waves-96100.png
  • 2)
    Physics-Waves-96101.png

  • Physics-Waves-96102.png

  • Physics-Waves-96103.png
Two sounding bodies producing progressive waves are given by
y1 = 4 sin 400πt and y2 = 3 sin 4047πt
One situated very near to the ears of a person, who will hear
  • 2 beats/s with intensity ratio 4/3 between maxima and minima
  • 2 beats/s with intensity ratio 49/1 between maxima and minima
  • 4 beats/s with intensity ratio 7/2 between maxima and minima
  • 4 beats/s with intensity ratio 4/3 between maxima and minima
Beats are produced by two waves given by, y1 = a sin 2000πt and y2 = a sin 2008πt. The number of beats heard per second is
  • zero
  • one
  • four
  • eight
Two tuning forks of frequency v1 and v2 produces n beats per second. If v2 and v are known, v1may be given by

  • Physics-Waves-96104.png
  • 2)
    Physics-Waves-96105.png

  • Physics-Waves-96106.png

  • Physics-Waves-96107.png
Two tuning forks P and Q when set vibrating give 4 beats/s. If a prong of the fork P is filed the beats are reduced to 2s -1. What is frequency of P, if that of Q is 250 Hz?
  • 246 Hz
  • 250 Hz
  • 254 Hz
  • 252 Hz
A set of 24 tuning forks are so arranged that each gives 6 beats/s with the previous one. If the frequency of the last tuning fork is double that of the first, frequency of the second tuning fork is
  • 138 Hz
  • 132 Hz
  • 144 Hz
  • 276 Hz
When two tuning forks (fork 1 and forkare sounded simultaneously, 4 beats/s are heard. Now, some tape is attached on the prong of the fork 2. When the tuning forks are sounded again, 6 beats/s are heard. If the frequency of fork 1 is 200 Hz, then what was the original frequency of fork 2?
  • 202 Hz
  • 200 Hz
  • 196 Hz
  • 204 Hz
A pipe of 30 cm long and open at both the ends produces harmonics. Which harmonic mode of pipe resonates a 1.1 kHz source? Given, speed of sound in air = 330 ms -1.
  • Fifth harmonic
  • Fourth harmonic
  • Third harmonic
  • Second harmonic
As shown in figure, a sound wave of wavelength 2.28 m enters the tube at S. Find the smallest radius of the circular path to hear minimum sound at D.
Physics-Waves-96108.png
  • 1.6 m
  • 1.3 m
  • 1.1 m
  • 1.0 m
A closed organ pipe and an open organ pipe of same length produce 2 beats/s while vibrating in their fundamental modes. The length of the open organ pipe is halved and that of closed pipe is doubled. Then the number of beats produced per second while vibrating in the fundamental mode is
  • 2
  • 6
  • 8
  • 7
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Physics Quiz Questions and Answers