FSc Part 1 Physics chapter 8: Waves MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

29 exam-style questions on Waves, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.

29 questions · 3 topics · 10 per test

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What chapter 8 covers

Ten Waves questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. In a transverse wave, the particles of the medium

  1. A
    vibrate perpendicular to the direction in which the wave travels
  2. B
    vibrate parallel to the direction in which the wave travels
  3. C
    travel along with the wave to the end of the medium
  4. D
    move in circles at constant speed
Show answer

Answer: A. In a transverse wave the particles vibrate at right angles to the direction of travel, forming crests and troughs. The wave carries energy, not matter.

2. A listener moves at 34 m s−1 towards a stationary source of frequency 680 Hz. The frequency heard is

  1. A
    748 Hz
  2. B
    612 Hz
  3. C
    680 Hz
  4. D
    756 Hz
Show answer

Answer: A. For a moving observer f' = (v + uo)f/v = (374/340) × 680 = 748 Hz. 612 Hz is for moving away; 756 Hz uses the moving-source formula.

3. The light from a distant galaxy shows a red shift in its spectral lines. This shows that the galaxy is

  1. A
    moving towards the Earth
  2. B
    moving away from the Earth
  3. C
    at rest relative to the Earth
  4. D
    getting hotter
Show answer

Answer: B. By the Doppler effect, a source moving away is observed at a lower frequency (longer wavelength), so its lines shift towards the red.

4. A pipe 0.50 m long is open at both ends. Taking the speed of sound as 340 m s−1, its fundamental frequency is

  1. A
    340 Hz
  2. B
    170 Hz
  3. C
    680 Hz
  4. D
    85 Hz
Show answer

Answer: A. For a pipe open at both ends f1 = v/2L = 340/1.0 = 340 Hz. 170 Hz is v/4L, the fundamental of a closed pipe of the same length.

5. A tuning fork of unknown frequency gives 5 beats per second with a 480 Hz fork. When the unknown fork is loaded with a little wax, the beats fall to 3 per second. The unknown frequency was

  1. A
    475 Hz
  2. B
    477 Hz
  3. C
    483 Hz
  4. D
    485 Hz
Show answer

Answer: D. The unknown is 475 or 485 Hz. Loading lowers its frequency; the beats decrease only if it moves closer to 480 Hz, so it was 485 Hz (now 483 Hz).

6. Newton assumed that sound travels through air isothermally, giving v = √(P/ρ). His value for the speed of sound in air at STP was about

  1. A
    332 m s−1
  2. B
    343 m s−1
  3. C
    280 m s−1
  4. D
    380 m s−1
Show answer

Answer: C. Newton's formula gives about 280 m s−1, roughly 16% below the measured 332 m s−1. The error was corrected by Laplace.

7. The pressure of air is increased while its temperature is kept constant. The speed of sound in it

  1. A
    increases
  2. B
    decreases
  3. C
    does not change, because P/ρ stays constant
  4. D
    doubles when the pressure doubles
Show answer

Answer: C. At constant temperature, doubling P also doubles ρ (Boyle's law), so P/ρ and therefore v = √(γP/ρ) do not change.

8. In a stationary wave, the distance between two adjacent nodes is

  1. A
    λ/4
  2. B
    λ/2
  3. C
    λ
  4. D
    2λ
Show answer

Answer: B. Nodes are half a wavelength apart, and so are adjacent antinodes. A node and the next antinode are λ/4 apart.

9. A pipe closed at one end has a fundamental frequency of 200 Hz. The next higher frequency at which it resonates is

  1. A
    400 Hz
  2. B
    600 Hz
  3. C
    800 Hz
  4. D
    300 Hz
Show answer

Answer: B. A closed pipe gives only odd harmonics: f, 3f, 5f ... So after 200 Hz comes 3 × 200 = 600 Hz. 400 Hz would need an even harmonic.

10. A car horn sounds at 500 Hz while the car approaches a stationary listener at 20 m s−1. The frequency heard is

  1. A
    471 Hz
  2. B
    500 Hz
  3. C
    531 Hz
  4. D
    529 Hz
Show answer

Answer: C. For an approaching source f' = vf/(v − us) = 340 × 500/320 = 531 Hz. 529 Hz uses the moving-observer formula by mistake.

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Ways to practise this chapter

Waves: questions students ask

How many Waves MCQs are there?

29, each with the answer and a short explanation, across 3 topics: Progressive waves and the speed of sound, Superposition, interference, beats and Doppler effect, Stationary waves in strings and air columns. Every chapter test draws ten of them, so you can take it many times.

Is the FSc Part 1 Physics chapter 8 test free?

Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.

How is the chapter test marked?

The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.

Can I read the explanations in Urdu?

Yes. In practice mode and on your results you can switch the explanations to Urdu.

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