1. A wave is a disturbance which:
a) Transfers matter from one point to another
b) Transfers energy without transfer of matter
c) Transfers both matter and energy
d) Does not transfer energy
Answer: b
Explanation: In waves, energy propagates while the medium’s particles only oscillate around equilibrium positions.
2. The velocity of a wave is given by:
a) 
b) 
c) 
d) 
Answer: a
Explanation: Wave velocity = wavelength × frequency.
3. Which of the following is a mechanical wave?
a) Light
b) Sound
c) Radio wave
d) X-ray
Answer: b
Explanation: Sound needs a material medium for propagation, hence mechanical.
4. Which of the following waves is longitudinal?
a) Sound wave in air
b) Water wave
c) Light wave
d) Seismic S-wave
Answer: a
Explanation: In longitudinal waves, particles oscillate parallel to wave motion → sound is longitudinal.
5. The SI unit of frequency is:
a) Hertz
b) Joule
c) Watt
d) Pascal
Answer: a
Explanation: 1 Hertz = 1 oscillation per second.
6. If a sound wave has a frequency of 500 Hz and wavelength of 0.68 m, its speed is:
a) 170 m/s
b) 340 m/s
c) 500 m/s
d) 680 m/s
Answer: b
Explanation: 
m/s.
7. In transverse waves, the particle motion is:
a) Parallel to wave motion
b) Perpendicular to wave motion
c) Random
d) Circular
Answer: b
Explanation: In transverse waves, oscillations are perpendicular to wave propagation.
8. Sound cannot travel in:
a) Solids
b) Liquids
c) Gases
d) Vacuum
Answer: d
Explanation: Sound needs a medium; cannot travel in vacuum.
9. Which property of wave does not change when it enters another medium?
a) Speed
b) Wavelength
c) Frequency
d) Amplitude
Answer: c
Explanation: Frequency is determined by the source and remains constant.
10. The time taken for one complete oscillation is called:
a) Wavelength
b) Frequency
c) Time period
d) Amplitude
Answer: c
Explanation: Time period is the reciprocal of frequency.
11. The energy carried by a wave is proportional to:
a) Frequency
b) Amplitude squared
c) Wavelength
d) Speed
Answer: b
Explanation: Wave energy ∝ 
.
12. A wave has a frequency of 100 Hz and period of:
a) 0.01 s
b) 0.1 s
c) 1 s
d) 10 s
Answer: a
Explanation: 
s.
13. The point on a wave where displacement is maximum is called:
a) Node
b) Antinode
c) Crest or trough
d) Wavelength
Answer: c
Explanation: Crest = maximum positive displacement; trough = maximum negative displacement.
14. The distance between two consecutive crests is:
a) Amplitude
b) Wavelength
c) Frequency
d) Period
Answer: b
Explanation: Wavelength = distance between successive identical points.
15. Which type of wave can be polarized?
a) Longitudinal wave
b) Transverse wave
c) Both
d) Neither
Answer: b
Explanation: Only transverse waves can be polarized.
16. In a stationary wave, the displacement is always zero at:
a) Antinode
b) Node
c) Crest
d) Trough
Answer: b
Explanation: Nodes are points of zero displacement.
17. The wave equation is:
a) 
b) 
c) Both (depending on wave direction)
d) Neither
Answer: c
Explanation: General wave equation can use ± depending on wave direction.
18. The speed of sound in air at 20°C is approximately:
a) 220 m/s
b) 280 m/s
c) 343 m/s
d) 400 m/s
Answer: c
Explanation: At 20°C, speed ≈ 343 m/s.
19. The ratio of speed of sound in solids, liquids, gases is generally:
a) Gas > liquid > solid
b) Solid > liquid > gas
c) Liquid > solid > gas
d) Same in all
Answer: b
Explanation: Because solids are most rigid, sound travels fastest in solids.
20. Which of the following is not a property of waves?
a) Reflection
b) Refraction
c) Diffraction
d) Combustion
Answer: d
Explanation: Combustion is a chemical reaction, not a wave property.
21. The loudness of sound depends on:
a) Frequency
b) Amplitude
c) Wavelength
d) Speed
Answer: b
Explanation: Loudness ∝ amplitude of sound wave.
22. The pitch of a sound depends on:
a) Amplitude
b) Frequency
c) Wavelength
d) Speed
Answer: b
Explanation: Higher frequency → higher pitch.
23. Which wave phenomenon explains sound heard around a corner?
a) Reflection
b) Refraction
c) Diffraction
d) Polarization
Answer: c
Explanation: Diffraction is bending of waves around obstacles.
24. The intensity of a wave is proportional to:
a) Amplitude
b) Amplitude²
c) Frequency
d) Wavelength
Answer: b
Explanation: Intensity ∝ square of amplitude.
25. The Doppler effect is the change in:
a) Wavelength due to amplitude
b) Frequency due to relative motion of source and observer
c) Speed due to medium
d) Energy of sound
Answer: b
Explanation: Doppler effect = change in observed frequency due to relative motion.
26. The equation of a progressive wave is 
. Its wavelength is:
a) 1.57 m
b) 2 m
c) 3.14 m
d) 4 m
Answer: b
Explanation: Wave equation: . Wavelength 
m. Correct = a.
27. The amplitude of resultant wave formed by superposition of two waves of same frequency and same amplitude is maximum when their phase difference is:
a) 0°
b) 90°
c) 120°
d) 180°
Answer: a
Explanation: Maximum amplitude occurs when waves are in phase.
28. The principle of superposition states that:
a) Only one wave can exist in a medium
b) Resultant displacement is sum of individual displacements
c) Waves always cancel each other
d) Waves always reinforce each other
Answer: b
Explanation: Principle: net displacement = vector sum of individual displacements.
29. Two sound waves of equal amplitude and slightly different frequencies interfere to produce:
a) Beats
b) Echo
c) Resonance
d) Standing waves
Answer: a
Explanation: Beats occur due to superposition of close-frequency waves.
30. A standing wave is formed due to:
a) Interference of two waves of same amplitude and frequency traveling in opposite directions
b) Reflection of sound only
c) Random oscillations
d) Beats
Answer: a
Explanation: Opposite moving identical waves form stationary (standing) waves.
31. In stationary waves, the points of zero displacement are called:
a) Crests
b) Troughs
c) Nodes
d) Antinodes
Answer: c
Explanation: At nodes, displacement = 0.
32. In stationary waves, maximum displacement occurs at:
a) Node
b) Antinode
c) Midpoint
d) Everywhere
Answer: b
Explanation: Antinodes are points of maximum amplitude.
33. The distance between two consecutive nodes in a stationary wave is:
a) 
b) 
c)
d) 2
Answer: a
Explanation: Node–node separation = half wavelength.
34. The fundamental frequency of a string fixed at both ends is:
a) 
b) 
c)
d)
Answer: a
Explanation: 
, where = speed of wave on string.
35. In the fundamental mode of vibration of a closed organ pipe:
a) Node at closed end, antinode at open end
b) Antinode at both ends
c) Node at both ends
d) Antinode at closed end, node at open end
Answer: a
Explanation: Closed end = displacement node, open end = displacement antinode.
36. In stationary waves, the distance between node and antinode is:
a)
b)
c)
d)
Answer: c
Explanation: Node–antinode separation = quarter wavelength.
37. In a stationary wave, energy transfer between particles is:
a) Maximum
b) Zero
c) Equal to progressive wave
d) Double
Answer: b
Explanation: Stationary waves do not transfer energy; only store energy between particles.
38. If the equation of wave is , the wave is moving:
a) In +x direction
b) In –x direction
c) In +y direction
d) Stationary
Answer: b
Explanation: Form indicates propagation in –x direction.
39. If the displacement of a particle in wave is 
, the speed of wave is:
a) 50/π m/s
b) 100/π m/s
c) 25/π m/s
d) π/50 m/s
Answer: a
Explanation: 
, 
. Speed 
.
40. A string 1 m long vibrates in fundamental mode with frequency 200 Hz. Speed of wave is:
a) 200 m/s
b) 400 m/s
c) 100 m/s
d) 50 m/s
Answer: b
Explanation: 
m/s.
41. If two waves superpose destructively, the amplitude becomes:
a) Maximum
b) Zero
c) Doubled
d) Half
Answer: b
Explanation: Destructive interference cancels amplitude.
42. Which condition is necessary for formation of stationary waves?
a) Same frequency
b) Same amplitude
c) Opposite directions
d) All of these
Answer: d
Explanation: For stationary waves: same frequency, amplitude, direction opposite.
43. In the 2nd harmonic of a string, number of antinodes is:
a) 1
b) 2
c) 3
d) 4
Answer: b
Explanation: Second harmonic → 2 loops → 2 antinodes.
44. The wave equation is 
. Its period is:
a) 0.031 s
b) 0.05 s
c) 0.1 s
d) 0.2 s
Answer: b
Explanation: 
, 
s. Correct = a.
45. In stationary waves, pressure variation nodes occur at:
a) Displacement nodes
b) Displacement antinodes
c) Midpoints
d) Everywhere
Answer: b
Explanation: Pressure node ↔ displacement antinode; pressure antinode ↔ displacement node.
46. The frequency of nth harmonic in open organ pipe is:
a) 
b)
c) 
d) 
Answer: a
Explanation: Open pipe supports all harmonics: 
.
47. In closed organ pipe, the frequencies present are:
a) Only even harmonics
b) Only odd harmonics
c) Both even and odd
d) None
Answer: b
Explanation: Closed pipe supports odd harmonics: 
.
48. In stationary waves, adjacent nodes are separated by:
a)
b)
c)
d)
Answer: b
Explanation: Node–node separation = .
49. When two identical waves superimpose in opposite directions, the wave velocity becomes:
a) Zero
b) Double
c) Same as original
d) Infinite
Answer: c
Explanation: Velocity of component waves unchanged; resultant is standing but wave speed is same.
50. In superposition, if phase difference is 90°, resultant amplitude is:
a) 
b) 
c) 
d)
Answer: c
Explanation: At phase difference 90°, 
.
51. Sound waves in air are:
a) Longitudinal
b) Transverse
c) Electromagnetic
d) Polarized
Answer: a
Explanation: Sound propagates as longitudinal compressions and rarefactions.
52. The speed of sound increases with:
a) Decrease in temperature
b) Increase in humidity
c) Decrease in pressure
d) Vacuum
Answer: b
Explanation: More water vapor lowers effective density of air, increasing sound speed.
53. The audible frequency range for humans is:
a) 0–100 Hz
b) 20–20,000 Hz
c) 200–2000 Hz
d) Above 20,000 Hz
Answer: b
Explanation: Human ears detect frequencies in the range 20 Hz to 20 kHz.
54. Sound waves with frequency above 20,000 Hz are called:
a) Infrasonic
b) Supersonic
c) Ultrasonic
d) Subsonic
Answer: c
Explanation: Ultrasonic waves are >20 kHz.
55. The loudness of sound depends on:
a) Frequency
b) Amplitude
c) Speed
d) Medium
Answer: b
Explanation: Loudness ∝ square of amplitude.
56. The pitch of a sound is determined by:
a) Amplitude
b) Frequency
c) Wavelength
d) Speed
Answer: b
Explanation: Higher frequency = higher pitch.
57. Two tuning forks of frequency 256 Hz and 260 Hz are sounded together. The number of beats per second is:
a) 2
b) 3
c) 4
d) 5
Answer: b
Explanation: Beat frequency = 
. Correct = c.
58. The time interval between two successive compressions in air of frequency 200 Hz is:
a) 0.002 s
b) 0.005 s
c) 0.01 s
d) 0.02 s
Answer: c
Explanation: 
s. Correct = b.
59. The reflection of sound producing multiple echoes in auditorium is called:
a) Reverberation
b) Resonance
c) Diffraction
d) Doppler effect
Answer: a
Explanation: Persistence of sound due to multiple reflections = reverberation.
60. The phenomenon when frequency of sound heard is different due to relative motion is:
a) Echo
b) Resonance
c) Doppler effect
d) Beats
Answer: c
Explanation: Doppler effect = change in frequency due to motion of source/observer.
61. A train sounding a whistle of frequency 500 Hz approaches a stationary listener at 20 m/s. Speed of sound = 340 m/s. The apparent frequency is:
a) 529 Hz
b) 471 Hz
c) 515 Hz
d) 540 Hz
Answer: a
Explanation: 
Hz.
62. If the source of sound moves away from observer, the observed frequency:
a) Increases
b) Decreases
c) Remains same
d) Becomes zero
Answer: b
Explanation: Doppler effect: receding source → lower observed frequency.
63. If a tuning fork of frequency 512 Hz produces 4 beats per second with another fork, the other fork may have frequency:
a) 508 Hz or 516 Hz
b) 504 Hz or 520 Hz
c) 512 Hz
d) 500 Hz
Answer: a
Explanation: Beat frequency = 4 → other fork = 512 ± 4.
64. The natural frequency of an object depends on:
a) Shape
b) Size
c) Material
d) All of these
Answer: d
Explanation: Natural frequency depends on mass, shape, material, size.
65. Resonance occurs when:
a) Driving frequency = natural frequency
b) Amplitude = zero
c) Wavelength = amplitude
d) None
Answer: a
Explanation: Resonance = maximum amplitude oscillation at natural frequency.
66. Which phenomenon is used in tuning musical instruments?
a) Beats
b) Echo
c) Diffraction
d) Polarization
Answer: a
Explanation: Beats help musicians tune instruments by matching frequencies.
67. Which of the following is an example of resonance?
a) Swing pushed at regular intervals
b) Tuning fork vibrating near another of same frequency
c) Shattering of glass by loud sound
d) All of these
Answer: d
Explanation: All are resonance examples.
68. The quality or timbre of a sound depends on:
a) Frequency
b) Amplitude
c) Waveform (overtones)
d) Speed
Answer: c
Explanation: Timbre depends on waveform and overtones.
69. If the speed of sound in air is 330 m/s, the wavelength of 660 Hz sound is:
a) 0.25 m
b) 0.5 m
c) 1 m
d) 2 m
Answer: b
Explanation: 
m.
70. The minimum distance for echo to be heard clearly is:
a) 17 m
b) 34 m
c) 50 m
d) 100 m
Answer: b
Explanation: Echo requires delay ≥0.1 s. At 340 m/s → distance = 340×0.1/2 = 17 m (one-way). For echo: minimum object distance = 17 m. Correct = a.
71. A sonometer wire resonates with tuning fork at 256 Hz when length is 0.5 m. Velocity of wave on wire is:
a) 128 m/s
b) 256 m/s
c) 512 m/s
d) 1024 m/s
Answer: c
Explanation: 
. Correct = b.
72. The phenomenon of sound heard after reflection from a distant surface is:
a) Echo
b) Beats
c) Resonance
d) Refraction
Answer: a
Explanation: Echo = reflected sound heard separately.
73. The persistence of sound due to multiple reflections is undesirable in halls. It is reduced by:
a) Using hard walls
b) Using soft materials like curtains
c) Using smooth ceilings
d) Increasing reflection
Answer: b
Explanation: Absorbing materials reduce reverberation.
74. In resonance tube experiment, if first resonance occurs at 20 cm, second will occur at:
a) 40 cm
b) 60 cm
c) 80 cm
d) 100 cm
Answer: b
Explanation: Closed pipe resonance → successive resonance positions differ by .
75. Beats are heard when two sounds of frequencies:
a) Widely different
b) Slightly different
c) Same
d) One is zero
Answer: b
Explanation: Beat phenomenon occurs when frequency difference ≤ 10 Hz (approx.).
76. The wave equation is given by 
. The wavelength is:
a) 2 m
b) 4 m
c) 5 m
d) 10 m
Answer: c
Explanation: Equation form: 
. Here coefficient of = 0.2 → 
. So 
m.
77. A string 2 m long is vibrating in fundamental mode. Wave speed = 100 m/s. Frequency is:
a) 25 Hz
b) 50 Hz
c) 100 Hz
d) 200 Hz
Answer: b
Explanation: 
. Correct = a.
78. The frequency of nth harmonic of a closed organ pipe is proportional to:
a) 
b) 
c) Odd multiples of fundamental
d) Square of
Answer: c
Explanation: Closed pipe supports only odd harmonics (1st, 3rd, 5th …).
79. Which of the following is not a characteristic of stationary waves?
a) Presence of nodes and antinodes
b) Energy transfer along the medium
c) Formed by superposition of two opposite waves
d) No progressive wave motion
Answer: b
Explanation: Stationary waves do not transfer energy.
80. Two waves of amplitudes each superpose in opposite phase. Resultant amplitude is:
a) 0
b) a
c) 2a
d) None
Answer: a
Explanation: Destructive interference → amplitudes cancel.
81. The velocity of transverse wave on a stretched string depends on:
a) Tension only
b) Mass per unit length only
c) Tension and mass per unit length
d) Length of string
Answer: c
Explanation: 
, where = mass/length.
82. The fundamental frequency of a string is 200 Hz. Its third harmonic is:
a) 400 Hz
b) 600 Hz
c) 800 Hz
d) 100 Hz
Answer: b
Explanation: Harmonics are integral multiples: 
.
83. The speed of sound in hydrogen is about:
a) Same as in oxygen
b) √(M
/M) times faster
c) Slower than in oxygen
d) Independent of gas
Answer: b
Explanation: 
. Hydrogen lighter than oxygen → sound faster.
84. The energy of a wave is proportional to:
a) Frequency
b) Amplitude squared
c) Wavelength
d) Speed
Answer: b
Explanation: Wave energy ∝ .
85. In a resonance column experiment, air column resonates with tuning fork at 32 cm and again at 100 cm. Wavelength of sound is:
a) 34 cm
b) 68 cm
c) 136 cm
d) 200 cm
Answer: c
Explanation: Difference between resonant lengths = → cm.
86. If the length of a closed organ pipe is doubled, its fundamental frequency becomes:
a) Half
b) Double
c) Same
d) Four times
Answer: a
Explanation: . Doubling halves frequency.
87. When two sound waves of slightly different frequencies interfere, the phenomenon heard is:
a) Echo
b) Beats
c) Resonance
d) Reverberation
Answer: b
Explanation: Beats = periodic rise and fall of sound intensity.
88. If two progressive waves having same amplitude and frequency move in opposite direction, they produce:
a) Interference
b) Stationary waves
c) Beats
d) Random waves
Answer: b
Explanation: Opposite waves of same frequency = stationary wave.
89. The first overtone of a closed organ pipe is its:
a) 2nd harmonic
b) 3rd harmonic
c) 4th harmonic
d) Fundamental
Answer: b
Explanation: Closed pipe supports only odd harmonics → 1st overtone = 3rd harmonic.
90. The apparent frequency heard when source moves towards observer is given by:
a) 
b)
c) 
d) 
Answer: b
Explanation: For approaching source: .
91. A wave is represented by . Frequency is:
a) 50 Hz
b) 100 Hz
c) 200 Hz
d) 400 Hz
Answer: b
Explanation: 
.
92. A sound wave travels from air into water. Which quantity remains unchanged?
a) Wavelength
b) Speed
c) Frequency
d) Amplitude
Answer: c
Explanation: Frequency is independent of medium.
93. The fundamental frequency of open pipe of length L is:
a)
b)
c)
d)
Answer: a
Explanation: For open pipe: .
94. The loudness of sound is measured in:
a) Joule
b) Watt
c) Decibel
d) Hertz
Answer: c
Explanation: Loudness is measured in dB.
95. Which of the following is not an application of ultrasound?
a) Cleaning
b) SONAR
c) Medical imaging
d) Radio broadcasting
Answer: d
Explanation: Ultrasound is not used in radio.
96. If a wave has frequency 500 Hz and wavelength 0.68 m, its velocity is:
a) 200 m/s
b) 250 m/s
c) 300 m/s
d) 340 m/s
Answer: d
Explanation: .
97. Which of the following is an example of transverse wave?
a) Sound in air
b) Light wave
c) Seismic P-wave
d) Compressions in slinky
Answer: b
Explanation: Light is transverse.
98. Which of the following travels with maximum speed in air?
a) Sound
b) Light
c) Ultrasonic
d) Infrasonic
Answer: b
Explanation: Light travels at 
m/s, much faster than sound.
99. In stationary waves, distance between two adjacent nodes is:
a)
b)
c)
d)
Answer: b
Explanation: Node–node distance = half wavelength.
100. SONAR is based on:
a) Doppler effect
b) Total internal reflection
c) Echo principle
d) Diffraction
Answer: c
Explanation: SONAR uses reflection (echo) of ultrasound waves.