Sound

Physics, SSC-Punjab Class 10. This chapter is split into 38 topics and has 917 practice questions. The topics covered are listed below, followed by 10 free sample questions from the chapter.

Topics in this chapter

1. Speed of sound in various media data 25 questions
2. Propagation of sound through a medium 24 questions
3. Speed of sound and the medium 23 questions
4. Uses of infrasound 21 questions
5. Noise pollution effects and control 21 questions
6. Thunder and lightning distance 25 questions
7. Echo and reflection of sound 23 questions
8. Travel time of sound in different media 24 questions
9. Tuning fork activities showing vibrations 20 questions
10. Production of sound by vibrations 22 questions
11. Echo calculations: time of return 25 questions
12. Comparing speeds of sound in air, water and solids 24 questions
13. Longitudinal nature of sound waves 21 questions
14. Exercise style questions on sound 27 questions
15. Musical sounds and noise 21 questions
16. Measuring the speed of sound by the echo method 23 questions
17. Audible frequency range and infrasound 23 questions
18. Wavelength of sound from speed and frequency 30 questions
19. Speed of sound from frequency and wavelength 30 questions
20. Distinct echo minimum distance and 0.1 s rule 22 questions
21. Pitch and frequency of sound 24 questions
22. Integrated sound numericals 28 questions
23. Frequency of sound from speed and wavelength 30 questions
24. Common misconceptions about sound 21 questions
25. SONAR echo time and object detection 24 questions
26. Acoustic protection of buildings 21 questions
27. Ultrasound properties and uses 23 questions
28. Bell jar experiment on sound in vacuum 22 questions
29. SONAR depth of sea calculations 30 questions
30. Echo location by bats and medical scanning numerical items 27 questions
31. Refraction and diffraction of sound 24 questions
32. Echo calculations: distance of the reflector 30 questions
33. Quality of sound and oscilloscope traces 23 questions
34. Wavelengths and frequencies of infrasound and ultrasound 29 questions
35. Frequency and period of repeated sounds 24 questions
36. Loudness of sound 22 questions
37. Echo experiments and speed of sound measurement 21 questions
38. SONAR concept and working 20 questions

Sample questions: Sound

10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.

Q1. A boatman on a lake wants to hear a distinct echo, which needs a delay of at least 0.1 s. Taking the speed of sound as 332 m s⁻¹, which of these distances from the far shore cliff is suitable?

• A. 45 m(correct answer)
• B. 3 m
• C. 11 m
• D. 15 m

Answer: A.For a delay of at least 0.1 s the far shore cliff must be at least 332 × 0.1 / 2 = 16.6 m away; 45 m satisfies this while the other distances are too near.

Q2. The thunder arrives 10 s after the flash of lightning. If sound travels at 340 m s⁻¹, how far is the storm cloud?

• A. 34 m
• B. 1700 m
• C. 6800 m
• D. 3400 m(correct answer)

Answer: D.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 10 = 3400 m. Halving is only for echoes, which go there and back.

Q3. A flash of lightning is seen 1.5 s before the thunder is heard. How far away did the lightning strike? (speed of sound 340 m s⁻¹)

• A. 510 m(correct answer)
• B. 226.7 m
• C. 1020 m
• D. 255 m

Answer: A.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 1.5 = 510 m. Halving is only for echoes, which go there and back.

Q4. The thunder arrives 2.5 s after the flash of lightning. If sound travels at 340 m s⁻¹, how far is the storm cloud?

• A. 136 m
• B. 425 m
• C. 850 m(correct answer)
• D. 1700 m

Answer: C.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 2.5 = 850 m. Halving is only for echoes, which go there and back.

Q5. A child counts 12 s between seeing a lightning flash and hearing the thunder (sound speed 343 m s⁻¹). How far away is the flash?

• A. 4116 m(correct answer)
• B. 8232 m
• C. 28.58 m
• D. 2058 m

Answer: A.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 343 × 12 = 4116 m. Halving is only for echoes, which go there and back.

Q6. The thunder arrives 0.5 s after the flash of lightning. If sound travels at 340 m s⁻¹, how far is the storm cloud?

• A. 680 m
• B. 170 m(correct answer)
• C. 85 m
• D. 340 m

Answer: B.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 0.5 = 170 m. Halving is only for echoes, which go there and back.

Q7. A flash of lightning is seen 3.5 s before the thunder is heard. How far away did the lightning strike? (speed of sound 340 m s⁻¹)

• A. 1190 m(correct answer)
• B. 595 m
• C. 2380 m
• D. 97.14 m

Answer: A.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 3.5 = 1190 m. Halving is only for echoes, which go there and back.

Q8. A child counts 4.5 s between seeing a lightning flash and hearing the thunder (sound speed 343 m s⁻¹). How far away is the flash?

• A. 76.22 m
• B. 771.8 m
• C. 1544 m(correct answer)
• D. 3087 m

Answer: C.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 343 × 4.5 = 1544 m. Halving is only for echoes, which go there and back.

Q9. A child counts 6.5 s between seeing a lightning flash and hearing the thunder (sound speed 340 m s⁻¹). How far away is the flash?

• A. 4420 m
• B. 52.31 m
• C. 1105 m
• D. 2210 m(correct answer)

Answer: D.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 6.5 = 2210 m. Halving is only for echoes, which go there and back.

Q10. A flash of lightning is seen 30 s before the thunder is heard. How far away did the lightning strike? (speed of sound 340 m s⁻¹)

• A. 20400 m
• B. 10200 m(correct answer)
• C. 5100 m
• D. 11.33 m

Answer: B.Light arrives almost instantly, so the delay is the sound's travel time: d = vt = 340 × 30 = 10200 m. Halving is only for echoes, which go there and back.