Free Waves MCQs with Answers
1,281 Waves MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Progressive waves transfer energy through oscillations, with wavelength, frequency, amplitude and wave speed related by v = fλ; sound speed depends on the medium. Superposition produces interference and stationary waves in strings and organ pipes, while simple harmonic motion describes the oscillation itself and must be distinguished from wave propagation.
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- A. 3 m/s
- B. 6 m/s
- C. 9 m/s
- D. 12 m/s
Explanation: f = 54/60 = 0.9 Hz. v = f λ = 0.9 × 10 = 9 m/s. Thus, option C is correct.
Correct answer: 9 m/s- A. 409
- B. 429
- C. 517
- D. 500
Explanation: Doppler for moving source toward observer: f' = f × v/(v − vs ) = 450 × 330/(330 − 33) = 450 × 330/297 ≈ 450 × 1.111 = 500 Hz.
Correct answer: 500- A. 90 Hz
- B. 180 Hz
- C. 360 Hz
- D. 720 Hz
Explanation: Compression to adjacent rarefaction = λ/2 = 1 m ⇒ λ = 2 m. Then f = v/λ= 360/2 = 180 Hz.
Correct answer: 180 Hz- A. Wavelength
- B. Amplitude
- C. Mass
- D. Energy
Explanation: Waves transport energy and information through a medium (or field) without net transport of mass. Thus, option D is correct.
Correct answer: Energy- A. 0.5 m
- B. 1.0 m
- C. 1.5 m
- D. 2.0 m
Explanation: Since the wave is moving to the right, we can draw the position of the wave at the next instant by simply replicating the wave, but…
Correct answer: 0.5 m- A. Reflection
- B. Interference
- C. Diffraction
- D. Polarization
Explanation: Polarization (orientation of oscillation plane) is possible only for transverse waves.
Correct answer: Polarization- A. Density
- B. Elasticity
- C. Temperature
- D. Pressure
Explanation: In gases at fixed temperature, sound speed depends on temperature and molecular properties (and indirectly on density and elasticity).
Correct answer: Pressure708. When two waves of same frequency and travelling in the same direction are superimposed than we have?
- A. Interference
- B. Beats
- C. Standing wave
- D. Stationary wave
Explanation: Two co-propagating waves interfere; beats require slight frequency difference; standing waves require opposite directions.
Correct answer: Interference- A. 1
- B. 2
- C. 3
- D. 4
Explanation: Beat frequency equals absolute difference of frequencies. If difference = 2 Hz, observer hears 2 beats per second.
Correct answer: 2- A. π/4
- B. π/2
- C. π
- D. 2π
Explanation: When a wave is reflected from a denser medium to a rarer medium, there is a phase change of 0° or no phase change (or 360°).But if it was…
Correct answer: π- A. Sonic
- B. Infrasonic
- C. Ultrasonic
- D. Tidal
Explanation: "Sonic" refers to audible frequencies (roughly 20 Hz to 20 kHz) that stimulate human hearing; infrasonic/ultrasonic are outside audible…
Correct answer: Sonic- A. Amplitude
- B. Amplitude2
- C. Frequency
- D. Wavelength
Explanation: Wave energy increases rapidly with amplitude. E directly proportional to A square.
Correct answer: Amplitude2- A. Reflection
- B. Refraction
- C. Diffraction
- D. Interference
Explanation: When waves pass through a narrow opening or around an edge, they bend and spread out.
Correct answer: Diffraction- A. Progressive wave
- B. Stationary wave
- C. Transverse wave
- D. Longitudinal wave
Explanation: Stationary (standing) waves are produced when two waves of the same frequency and amplitude travel in opposite directions and interfere.
Correct answer: Stationary wave- A. ±A
- B. ±A/2
- C. Zero
- D. ±A/√2
Explanation: Kinetic energy is maximum where potential energy is minimum, i.e., at mean position x = 0 where speed is greatest.
Correct answer: Zero- A. Crest
- B. Trough
- C. Node
- D. Antinode
Explanation: At a node, particles do not move (zero amplitude). At an antinode, particles vibrate with maximum amplitude.
Correct answer: Node- A. Frequency changes
- B. Speed changes
- C. Amplitude remains same
- D. All of these
Explanation: When light or sound enters another medium, its speed and wavelength change, but frequency remains constant.
Correct answer: Speed changes- A. Air
- B. Water
- C. Iron
- D. Vacuum
Explanation: Sound travels fastest in solids because particles are closely packed.Approximate speeds:Air: 343 m/sWater: 1500 m/s Iron: 5100 m/s.
Correct answer: Iron- A. Interference
- B. Mechanical resonance
- C. Magnetic resonance
- D. Electric resonance
Explanation: Microwaves interact with polar molecules (water) causing dielectric heating via dipole rotation and absorption at microwave…
Correct answer: Electric resonance- A. 150 m/s
- B. 200 m/s
- C. 300 m/s
- D. 400 m/s
Explanation: Wave speed v = f × λ = 200 × 1.5 = 300 m/s.
Correct answer: 300 m/s