JEE Physics Waves MCQs Set A

Question: Which of the following phenomenon cannot take place with sound waves?

• a) Polarisation
• b) Refraction
• c) Diffraction
• d) Reflection

Answer: Polarisation

Question: The speed of sound in air is independent from its

• a) All of these
• b) Phase
• c) Frequency
• d) Amplitude

Answer: All of these

Question: The waves which cannot travel without medium are

• a) Sound waves
• b) Light waves
• c) Radio waves
• d) X-rays

Answer: Sound waves

Question: When a wave propagating through a medium encounters a change in medium, then which of the following property remains same?

• a) Frequency
• b) Wavelength
• c) Amplitude
• d) Speed

Answer: Frequency

Question: A transverse wave travels along x-axis. The particles of medium move

• a) Either along y-axis or z-axis
• b) Along y-axis
• c) Along x-axis
• d) Along z-axis

Answer: Either along y-axis or z-axis

Question: The phenomenon of sound propagation in air is

• a) An adiabatic process
• b) An isochoric process
• c) An isobaric process
• d) An isothermal process

Answer: An adiabatic process

Question:

• a)

  

• b)

  

• c) 600 m/s
• d) 400 m/s

Answer:

Question: In a stretched string

• a) Both transverse and longitudinal waves can exist
• b) Only transverse waves can exist
• c) Only longitudinal waves can exist
• d) None of these

Answer: Both transverse and longitudinal waves can exist

Question: Two strings of same material are stretched to the same tension. If their radii are in the ratio 1 : 2, then respective wave velocities in them will be in ratio

• a) 2 : 1
• b) 1 : 2
• c) 1 : 4
• d) 4 : 1

Answer: 2 : 1

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  Which of the following equations represents a transverse wave travelling along –y axis?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) A wave travelling in negative x-direction with a velocity of 1.5 m/s
• b) A wave travelling in positive x direction with a velocity of 1.5 m/s
• c) A wave travelling in negative x-direction with a velocity of 150 m/s
• d) A wave traveling in positive x-direction with wavelength 0.2 m

Answer:  A wave travelling in negative x-direction with a velocity of 1.5 m/s

Question:

• a)

  

• b)

  

• c)

  

• d) 0

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: In a simple harmonic wave, minimum distance between particles in same phase always having same speed, is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The sound intensity level at a point 4 m from the point source is 10 dB, then the sound level at a distance 2 m from the same source will be

• a) 16 dB
• b) 23 dB
• c) 32 dB
• d) 26 dB

Answer: 16 dB

Question: The tones that are separated by three octaves have a frequency ratio of

• a) 8
• b) 16
• c) 6
• d) 3

Answer: 8

Question:

• a) A₀
• b)

  

• c)

  

• d)

  

Answer: A₀

More Questions.........................

Question:

• a) 2A₀
• b) 2xA₀
• c) (x – 1)A₀
• d) (x + 1)A₀

Answer: 2A₀

Question: Which of the following represents a standing wave?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 3
• b) 6
• c) 4
• d) 1.5

Answer: 3

Question: In a stationary wave

• a) Strain is maximum at nodes
• b) Strain is maximum at antinodes
• c) Strain is minimum at nodes
• d) Amplitude is zero at all points

Answer: Strain is maximum at nodes

Question: Select the correct statement about the reflection and refraction of a wave at the interface between the medium 1 and 2 the

• a) Frequency of transmitted wave is same as that of incident wave
• b) Wavelength of reflected wave is less than that of incident wave
• c) Frequency of wave changes as per nature of boundary
• d)

  

Answer: Frequency of transmitted wave is same as that of incident wave

Question:

• a)

  

• b)

  

• c)

  

• d) 0

Answer:

Question: A 12 m long vibrating string has the speed of wave 48 m/s. To what frequency it will resonate?

• a) All of these
• b) 6 cps
• c) 4 cps
• d) 2 cps

Answer: All of these

Question: A certain string will resonant to several frequencies, the lowest of which is 200 cps. What are the next three higher frequencies to which it resonants?

• a) 400, 600, 800
• b) 300, 400, 500
• c) 100, 150, 200
• d) 200, 250, 300

Answer: 400, 600, 800

Question: The tension in a wire is decreased by 19%. The percentage decrease in frequency will be

• a) 10%
• b) 19%
• c) 0.9%
• d) 0.19%

Answer:  10%

Question:

• a) 200 Hz
• b) 150 Hz
• c) 600 Hz
• d) 450 Hz

Answer: 200 Hz

Question:  An aluminium rod having a length 100 cm is clamped at its middle point and set into longitudinal vibrations. Let the rod vibrate in its fundamental mode. The density of aluminium is 2600 kg/m³ and its Young’s modulus is 7.8 × 10¹⁰ N/m². The frequency of the sound produced is

• a) 2740 Hz
• b) 2350 Hz
• c) 1685 Hz
• d) 1250 Hz

Answer: 2740 Hz

Question: The string of a violin has a frequency of 440 cps. If the violin string is shortened by one fifth, its frequency will be changed to

• a) 2200 cps
• b) 550 cps
• c) 880 cps
• d) 440 cps

Answer: 2200 cps

Question: A wire of length one metre under a certain initial tension emits a sound of fundamental frequency 256 Hz. When the tension is increased by 1 kg wt, the frequency of the fundamental node increases to 320 Hz. The initial tension is

• a) 16/9 kg wt
• b) 20/9 kg wt
• c) 4/3 kg wt
• d) 3/4 kg wt

Answer: 16/9 kg wt

Question: In case of closed pipe which harmonic the p^th overtone will be

• a) 2p + 1
• b) 2p – 1
• c) p + 1
• d) p – 1

Answer: 2p + 1

Question:  The pitch of an organ pipe is highest when the pipe is filled with

• a) Hydrogen
• b) Oxygen
• c) Carbon dioxide
• d) Air

Answer: Hydrogen

Question: A cylindrical tube, open at both ends, has a fundamental frequency f in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of the air column is now

• a) f
• b) 2 f
• c)

  

• d)

  

Answer: f

Question: For a certain organ pipe, three successive resonance frequencies are observed at 425, 595, and 765, Hz respectively, Taking the speed of sound in air to be 340 m/s the fundamental frequency of the pipe (in Hz) is

• a) 85
• b) 245
• c) 170
• d) 425

Answer: 85

Question: A closed pipe of length 10 cm has its fundamental frequency half that of the second overtone of an open pipe. The length of the open pipe

• a) 30 cm
• b) 40 cm
• c) 20 cm
• d) 10 cm

Answer: 30 cm

Question:

• a) 1 : 2 : 4 : 3
• b) 4 : 2 : 3 : 1
• c) 6 : 2 : 3 : 4
• d) 12 : 6 : 3 : 4

Answer: 1 : 2 : 4 : 3

Question: In resonance tube two successive positions of resonance are obtained at 15 cm and 48 cm. If the frequency of the fork is 500 cps, the velocity of sound is

• a) 330 m/s
• b) 300 m/s
• c) 1000 m/s
• d) 360 m/s

Answer:  330 m/s

Question: During superposition of two waves of nearly equal frequencies, beats frequency is defined as the

• a) Number of times the resultant intensity becomes maximum or minimum in one second
• b) Sum of frequencies of interfering waves
• c) Average of frequencies of interfering waves
• d) Number of times the resultant amplitude becomes maximum or minimum in one second

Answer: Number of times the resultant intensity becomes maximum or minimum in one second

Question: A tuning fork of unknown frequency produces 4 beats per second when sounded with another tuning fork of frequency 254 Hz. It gives the same number of beats per second when unknown tuning fork loaded with wax. The unknown frequency before loading with wax is

• a) 258
• b) 254
• c) 250
• d) Can’t be determined

Answer: 258

Question: Ten tuning forks are arranged in increasing order of frequency in such a way that any two consecutive tuning forks produce 4 beats per second. The highest frequency is twice that of the lowest. Possible highest and lowest frequencies (in Hz) are

• a) 72 and 36
• b) 44 and 22
• c) 100 and 50
• d) 80 and 40

Answer: 72 and 36

Question:

• a) 3 beats per second with intensity relation between maxima and minima equal to 9
• b) 3 beats per second with intensity relation between maxima and minima equal to 2
• c) 6 beats per second with intensity relation between maxima and minima equal to 2
• d) 6 beats per second with intensity relation between maxima and minima equal to 9

Answer: 3 beats per second with intensity relation between maxima and minima equal to 9

Question: A tuning fork vibrating with a sonometer having a wire of length 20 cm produces 5 beats per second. The beats frequency does not change if the length of the wire is changed to 21 cm. The frequency of the tuning fork must be

• a) 205 Hz
• b) 215 Hz
• c) 210 Hz
• d) 200 Hz

Answer: 205 Hz

Question: A tuning fork and an air column whose temperature is 51°C produce 4 beats in one second, when sounded together. When the temperature of air column decreases the number of beats per second decreases. When the temperature remains 16°C only one beat per second is produced. The frequency of the tuning fork is

• a) 50 Hz
• b) 150 Hz
• c) 75 Hz
• d) 100 Hz

Answer: 50 Hz

Question:  A man standing on a platform observes that the frequency of the sound of a whistle emitted by a train drops by 140 Hz. If the velocity of sound in air is 330 m/s and the speed of the train is 70 m/s, the frequency of the whistle is

• a) 800 Hz
• b) 400 Hz
• c) 260 Hz
• d) 571 Hz

Answer: 800 Hz

Question:  A sound source is moving towards a stationary observer with (1/10) of the speed of sound. The ratio of apparent to real frequency is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d) 2

Answer:

Question:

• a) Zero
• b)

  

• c)

  

• d)

  

Answer: Zero

Question: The longitudinal wave can be observed in

• a) Elastic media
• b) Inelastic media
• c) Both
• d) None of these

Answer: Elastic media

Question: A transverse pulse is shown in the figure, on which 4 points are shown at any instant. Which of the following points are in a state to move upwards in subsequent time?

• a) B, C
• b) B, D
• c) A, D
• d) A, B

Answer:  B, C

Question: A rope of length L and mass M hangs freely from the ceiling. If the time taken by a transverse wave to travel from the bottom to the top of the rope is T, then time to cover first half length is

• a)

  

• b)

  

• c)

  

• d) T

Answer:

Question: A uniform rope having some mass hangs vertically from a rigid support. A transverse wave pulse is produced at the lower end. The speed (u) of the wave pulse varies with height (h) from the lower end as

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A transverse pulse generated at the bottom of a uniform rope of length L, travels in upward direction. The time taken by it to travel the full length of rope will be

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which one of the following represents a wave?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Only (a)
• b) (b) & (c)
• c) (c) & (d)
• d) Only (c)

Answer: Only (a)

Question: In a sinusoidal wave, the time required for a particular point to move from maximum displacement to zero displacement is 0.170 s. The frequency of wave is

• a) 1.47 Hz
• b) 2.94 Hz
• c) 0.36 Hz
• d) 0.73 Hz

Answer: 1.47 Hz

Question:

• a) a
• b) b
• c) c
• d) b and d

Answer: a

Question:  A sinusoidal wave of frequency 500 Hz has a speed of 350 m/s. The phase difference between two displacements at a certain point at times 1 m apart is

• a)

  

• b)

  

• c)

  

• d)

  

Answer: