A particle moves uniformly around a circle of radius 5.0 cm at 2.0 revolutions per second. What are the amplitude and frequency of the SHM performed by its projection on a diameter?
Correct answer B. 5.0 cm and 2.0 Hz
Topic / 30 questions
Waves MCQs
Waves MCQs cover wave motion and its terms, the speed of sound and Laplace's correction, superposition, stationary waves in strings and pipes, and simple harmonic motion. They help MDCAT, ECAT and FSc candidates revise concepts and short calculations, and every question on MCQs360 shows its correct answer instantly.
- Electromagnetic Induction 30
- Fluid Dynamics 30
- Electrostatics 30
- Electronics 30
- Electromagnetism 30
- Current Electricity 30
- Work and Energy 30
- Waves 30
- Vectors and Equilibrium 30
- Nuclear Physics 30
- Dawn of Modern Physics 30
- Thermodynamics 30
- Rotational and Circular Motion 30
- Atomic Spectra 30
- Alternating Current 30
- Force and Motion 30
A mass of 0.50 kg attached to a spring of spring constant 200 N/m oscillates horizontally. What is the period of oscillation?
Correct answer B. 0.31 s
A body performs simple harmonic motion. Which statement about its acceleration is correct?
Correct answer D. It is proportional to displacement and directed towards the mean position
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A stretched string vibrates with a fundamental frequency of 200 Hz. If the tension is made four times as large with nothing else changed, what is the new fundamental frequency?
Correct answer C. 400 Hz
Which harmonics can be produced by an organ pipe closed at one end?
Correct answer A. Only the odd harmonics
An organ pipe 0.50 m long is closed at one end. What is its fundamental frequency (speed of sound = 340 m/s)?
Correct answer B. 170 Hz
A string 0.80 m long is fixed at both ends, and transverse waves travel along it at 240 m/s. What is the frequency of its fundamental mode?
Correct answer A. 150 Hz
Which statement about a stationary wave is correct?
Correct answer D. It does not transfer energy along the medium
In a stationary wave, the distance between two adjacent nodes is ____.
Correct answer D. half a wavelength
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Two tuning forks of frequencies 256 Hz and 260 Hz are sounded together. How many beats are heard per second?
Correct answer D. 4
Two loudspeakers driven in phase emit sound of frequency 680 Hz. At a point, the path difference from the two speakers is 0.75 m. What is heard there (speed of sound = 340 m/s)?
Correct answer D. A minimum, due to destructive interference
Why does sound travel slightly faster in humid air than in dry air at the same temperature and pressure?
Correct answer A. Humid air has a lower density
Two coherent sound sources vibrate in phase. At a point where their path difference is a whole number of wavelengths, what is observed?
Correct answer A. Constructive interference giving loud sound
According to the principle of superposition, when two waves overlap the resultant displacement at any point is ____.
Correct answer A. the vector sum of the individual displacements
At the same temperature and pressure, oxygen is 16 times as dense as hydrogen. What is the ratio of the speed of sound in hydrogen to that in oxygen (assume equal γ)?
Correct answer B. 4 : 1
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The speed of sound in air at 0 °C is 332 m/s. Taking v ∝ √T, what is the speed of sound at 273 °C?
Correct answer B. 470 m/s
How is the speed of sound in air affected by a change in pressure at constant temperature?
Correct answer D. It is not affected
Using Laplace’s formula, what is the speed of sound in air at a pressure of 1.01 × 10⁵ Pa and density 1.29 kg/m³ (γ = 1.4)?
Correct answer B. 331 m/s
Laplace corrected Newton’s formula for the speed of sound because the compressions and rarefactions ____.
Correct answer D. occur too quickly for heat to be exchanged, making the process adiabatic
Newton derived the formula v = √(P/ρ) for the speed of sound by assuming that the propagation of sound through a gas is ____.
Correct answer C. isothermal
About Waves MCQs
Questions begin with mechanical and electromagnetic waves, transverse and longitudinal waves, wave terms such as amplitude, wavelength and period, and the wave equation v = fλ. Sound questions cover Newton's formula, Laplace's correction and the effect of pressure, temperature and density on the speed of sound. Further questions deal with superposition and interference, stationary waves with nodes and antinodes, and the harmonics of strings and of open and closed organ pipes. The unit ends with simple harmonic motion: its defining condition, the periods of a mass-spring system and a simple pendulum, and SHM as the projection of uniform circular motion on a diameter.
Key facts to remember
- Wave equation: v = fλ, where f = 1/T.
- Newton's formula for the speed of sound is v = √(P/ρ); Laplace corrected it to v = √(γP/ρ) because sound waves are adiabatic.
- At constant temperature the speed of sound in a gas does not depend on pressure, and v ∝ √T (absolute temperature).
- Adjacent nodes in a stationary wave are λ/2 apart; a node and the next antinode are λ/4 apart.
- An open pipe gives all harmonics, fₙ = nv/2L; a pipe closed at one end gives only odd harmonics, fₙ = nv/4L (n = 1, 3, 5, ...).
- In SHM, a = −ω²x; a mass on a spring has T = 2π√(m/k) and a simple pendulum T = 2π√(l/g).
Exams that include Waves MCQs
Pakistan
- MDCAT
- ECAT (UET)
- NUMS
- AKU
- FSc boards
India
- NEET
- JEE Main
Bangladesh
- HSC
- Medical Admission Test
How to prepare for Waves MCQs
- Learn why Laplace's correction was needed: compressions and rarefactions are too rapid for heat exchange, so the process is adiabatic, not isothermal.
- Draw the first three modes for strings, open pipes and closed pipes; most harmonic MCQs can be answered from the sketches.
- Remember that speed of sound in different gases at the same temperature and pressure varies as 1/√ρ.
- For SHM from circular motion, the amplitude is the circle's radius and the frequency equals the revolutions per second.
Frequently asked questions
Which exams ask Waves MCQs?
Waves is part of the FSc physics syllabus, so its MCQs appear in MDCAT, ECAT (UET), NUMS and AKU entry tests and in FSc board papers. Students in India meet the same ideas in NEET and JEE Main, and Bangladeshi students in HSC and the medical admission test.
Why does a closed organ pipe give only odd harmonics?
A pipe closed at one end must have a node at the closed end and an antinode at the open end. Only standing waves with an odd number of quarter wavelengths fit this condition, so the allowed frequencies are fₙ = nv/4L with n = 1, 3, 5 and so on.
Last reviewed October 2026