A few extra questions in this Physics Chapter 10 Sound Waves: Characteristics and Applications from NCERT book.
Below are some of the top points from the chapter for a quick revision –
- Sound is produced by vibrating objects.
- Sound requires a material medium.
- Sound cannot travel through vacuum.
- Sound propagates as compressions and rarefactions.
- Sound is a longitudinal mechanical wave.
- Particles vibrate; energy propagates through medium.
- Crest represents maximum density region.
- Trough represents minimum density region.
- Wavelength (λ) SI unit is metre (m).
- Frequency (ν) SI unit is hertz (Hz).
- Time period (T) SI unit second (s).
- Frequency and time period: ν = 1/T.
- Speed of sound: v = λν.
- Amplitude determines sound energy and intensity.
- Sound travels fastest in solids.
35 MCQ Questions for Class 10 Science: Chapter 10 Sound Waves: Characteristics and Applications
Question 1. Sound is produced by:
a) Heat
b) Vibrations
c) Light
d) Magnetism
Answer:
b) Vibrations — Vibrating objects produce sound.
Question 2. The source of sound must:
a) Glow
b) Vibrate
c) Rotate
d) Expand
Answer:
b) Vibrate — Vibration creates sound waves.
Question 3. Human sound is produced by:
a) Tongue
b) Teeth
c) Vocal cords
d) Lips
Answer:
c) Vocal cords — Located in larynx.
Question 4. Sound can travel through:
a) Solids only
b) Liquids only
c) Gases only
d) All three
Answer:
d) All three — Needs a material medium.
Question 5. Sound cannot travel through:
a) Water
b) Steel
c) Air
d) Vacuum
Answer:
d) Vacuum — No medium available.
Question 6. Vacuum bell jar experiment proves:
a) Sound needs medium
b) Sound creates light
c) Air creates sound
d) Metals vibrate
Answer:
a) Sound needs medium — Sound disappears in vacuum.
Question 7. A region of high density is:
a) Trough
b) Rarefaction
c) Compression
d) Node
Answer:
c) Compression — Particles packed closer.
Question 8. A region of low density is:
a) Compression
b) Rarefaction
c) Crest
d) Amplitude
Answer:
b) Rarefaction — Particles spread apart.
Question 9. Sound waves consist of:
a) Crests only
b) Troughs only
c) Compression and rarefaction
d) Electrons
Answer:
c) Compression and rarefaction — Alternate density regions.
Question 10. Sound wave is a:
a) Transverse wave
b) Mechanical wave
c) Electromagnetic wave
d) Light wave
Answer:
b) Mechanical wave — Requires medium.
Question 11. Sound wave is:
a) Longitudinal
b) Transverse
c) Surface
d) Standing
Answer:
a) Longitudinal — Vibrations parallel propagation.
Question 12. Particles vibrate:
a) Perpendicular to propagation
b) Randomly only
c) Parallel to propagation
d) Circularly
Answer:
c) Parallel to propagation — Longitudinal wave property.
Question 13. What travels with sound?
a) Air particles
b) Energy
c) Source material
d) Dust particles
Answer:
b) Energy — Particles only oscillate.
Question 14. Particles of medium:
a) Move with wave
b) Stay fixed
c) Oscillate about mean position
d) Disappear
Answer:
c) Oscillate about mean position — Energy transfers.
Question 15. Highest point of wave:
a) Trough
b) Crest
c) Compression
d) Node
Answer:
b) Crest — Maximum density point.
Question 16. Lowest point of wave:
a) Crest
b) Antinode
c) Rarefaction
d) Trough
Answer:
d) Trough — Minimum density point.
Question 17. SI unit of wavelength:
a) Hz
b) m
c) s
d) m/s
Answer:
b) m — Length quantity.
Question 18. Symbol of wavelength:
a) ν
b) T
c) λ
d) v
Answer:
c) λ — Greek letter lambda.
Question 19. Frequency is measured in:
a) Metre
b) Second
c) Hertz
d) Joule
Answer:
c) Hertz — Oscillations per second.
Question 20. Symbol of frequency:
a) λ
b) ν
c) T
d) A
Answer:
b) ν — Greek letter nu.
Question 21. Time period symbol is:
a) λ
b) ν
c) T
d) v
Answer:
c) T — Time for oscillation.
Question 22. Relation between frequency and time period:
a) ν = T
b) ν = T²
c) ν = 1/T
d) T = ν²
Answer:
c) ν = 1/T — Inverse relationship.
Question 23. Frequency increases when:
a) Time period increases
b) Time period decreases
c) Amplitude increases
d) Wavelength increases
Answer:
b) Time period decreases — Inverse relation.
Question 24. Wavelength is distance between:
a) Crest and trough
b) Two consecutive crests
c) Two amplitudes
d) Two sources
Answer:
b) Two consecutive crests — One full cycle.
Question 25. Speed of sound formula:
a) v = λν
b) v = λ/T²
c) v = ν/T
d) v = λ+ν
Answer:
a) v = λν — Fundamental relation.
Question 26. SI unit of sound speed:
a) m
b) Hz
c) s
d) m/s
Answer:
d) m/s — Distance per time.
Question 27. Amplitude represents:
a) Maximum density change
b) Wave speed
c) Frequency
d) Time period
Answer:
a) Maximum density change — From average density.
Question 28. Greater amplitude means:
a) Less energy
b) More energy
c) Lower frequency
d) Less intensity
Answer:
b) More energy — Energy depends amplitude.
Question 29. Intensity is sound energy passing:
a) Unit area per time
b) Unit mass
c) Unit volume
d) Unit distance
Answer:
a) Unit area per time — Energy flow rate.
Question 30. Intensity decreases because sound:
a) Gains energy
b) Spreads over larger area
c) Stops vibrating
d) Changes frequency
Answer:
b) Spreads over larger area — Energy distributed.
Question 31. Sound travels fastest in:
a) Air
b) Water
c) Steel
d) Vacuum
Answer:
c) Steel — Particles closely packed.
Question 32. Approximate sound speed in air:
a) 1500 m/s
b) 340 m/s
c) 5000 m/s
d) 300000 km/s
Answer:
b) 340 m/s — Near room conditions.
Question 33. Sound speed increases with:
a) Lower temperature
b) Vacuum
c) Temperature
d) Darkness
Answer:
c) Temperature — Faster particle interactions.
Question 34. Microphone converts:
a) Electrical to sound
b) Sound to electrical
c) Heat to sound
d) Light to sound
Answer:
b) Sound to electrical — Vibrating diaphragm.
Question 35. Speaker converts:
a) Sound to light
b) Heat to sound
c) Electrical to sound
d) Sound to electrical
Answer:
c) Electrical to sound — Vibrating cone produces sound.
10 True and False Questions for Chapter 10 Sound Waves: Characteristics and Applications
Question 1. Sound is produced by vibrating objects. (True/False)
Answer:
True
Question 2. Sound can travel through a vacuum. (True/False)
Answer:
False
Question 3. Sound waves are longitudinal waves. (True/False)
Answer:
True
Question 4. Compressions are regions of low particle density. (True/False)
Answer:
False
Question 5. Frequency and time period are inversely related. (True/False)
Answer:
True
Question 6. The SI unit of frequency is hertz (Hz). (True/False)
Answer:
True
Question 7. Greater amplitude means greater sound intensity. (True/False)
Answer:
True
Question 8. Sound travels faster in air than in steel. (True/False)
Answer:
False
Question 9. A microphone converts sound into electrical signals. (True/False)
Answer:
True
Question 10. Sound speed decreases as temperature increases. (True/False)
Answer:
False
10 Fill in the Blanks Questions for Chapter 10 Sound Waves: Characteristics and Applications
Question 1. Sound is produced due to __________ of objects.
Answer:
Vibrations
Question 2. Sound cannot travel through a __________.
Answer:
Vacuum
Question 3. Regions of high particle density are called __________.
Answer:
Compressions
Question 4. The SI unit of frequency is __________.
Answer:
Hertz
Question 5. The SI unit of wavelength is __________.
Answer:
Metre
Question 6. The relationship between frequency and time period is ν = __________.
Answer:
1/T
Question 7. The speed of sound is given by v = __________.
Answer:
λν
Question 8. Greater __________ results in a louder sound.
Answer:
Amplitude
Question 9. Sound travels fastest in __________.
Answer:
Solids
Question 10. A microphone converts sound into __________ signals.
Answer:
Electrical
Question on Match the Columns
Unmatched Columns – Questions
| Column A | Column B |
|---|---|
| (i) Compression | (a) Sound to electrical signals |
| (ii) Rarefaction | (b) Distance between successive crests |
| (iii) Frequency | (c) Region of low particle density |
| (iv) Wavelength | (d) Region of high particle density |
| (v) Microphone | (e) Number of oscillations per second |
| (vi) Speed of Sound | (f) Product of wavelength and frequency |
Matched Columns – Answer
| Column A | Column B |
|---|---|
| (i) Compression | (d) Region of high particle density |
| (ii) Rarefaction | (c) Region of low particle density |
| (iii) Frequency | (e) Number of oscillations per second |
| (iv) Wavelength | (b) Distance between successive crests |
| (v) Microphone | (a) Sound to electrical signals |
| (vi) Speed of Sound | (f) Product of wavelength and frequency |
Related Class 9 Physics Chapters
Sound uses ideas from motion and energy. Revise them here:
- Describing Motion Around Us MCQs – speed, distance and time sums.
- Work, Energy and Simple Machines MCQs – sound is a form of energy.
- How Forces Affect Motion MCQs – vibration and restoring force.
Practise the numericals
Next chapter: Chapter 11 – Reproduction: How Life Continues
See all chapters: MCQ Questions for Class 9 Science – All 13 Chapters
