MCQs
1. Sound is produced due to:
A. Heat
B. Vibrations
C. Light
D. Pressure only
Answer: B
2. The periodic to and fro motion of an object is called:
A. Reflection
B. Refraction
C. Vibration
D. Radiation
Answer: C
3. The source of sound in humans is:
A. Tongue
B. Teeth
C. Vocal cords
D. Nose
Answer: C
4. A tuning fork produces sound when:
A. Heated
B. Vibrated
C. Painted
D. Bent
Answer: B
5. Sound can travel through:
A. Solids only
B. Liquids only
C. Gases only
D. Solids, liquids and gases
Answer: D
6. Sound cannot travel through:
A. Air
B. Water
C. Steel
D. Vacuum
Answer: D
7. The material through which sound propagates is called:
A. Medium
B. Source
C. Reflector
D. Receiver
Answer: A
8. Sound waves are:
A. Electromagnetic waves
B. Mechanical waves
C. Light waves
D. Transverse waves only
Answer: B
9. In a sound wave, regions of high density are called:
A. Rarefactions
B. Nodes
C. Compressions
D. Crests
Answer: C
10. Regions of low density in a sound wave are:
A. Compressions
B. Rarefactions
C. Troughs
D. Nodes
Answer: B
11. Sound waves in air are:
A. Transverse waves
B. Surface waves
C. Longitudinal waves
D. Electromagnetic waves
Answer: C
12. In longitudinal waves, particles vibrate:
A. Perpendicular to wave direction
B. Parallel to wave direction
C. Randomly
D. Circularly
Answer: B
13. The distance between two consecutive compressions is called:
A. Frequency
B. Amplitude
C. Wavelength
D. Time period
Answer: C
14. SI unit of wavelength is:
A. Hertz
B. Metre
C. Second
D. Decibel
Answer: B
15. Frequency is the number of oscillations per:
A. Minute
B. Hour
C. Unit time
D. Distance
Answer: C
16. SI unit of frequency is:
A. Metre
B. Hertz
C. Joule
D. Newton
Answer: B
17. Time period is:
A. Time taken for one oscillation
B. Distance travelled in one second
C. Maximum displacement
D. Number of waves
Answer: A
18. Frequency and time period are related as:
\nu=\frac{1}{T}
A. ν = T
B. ν = 1/T
C. ν = T²
D. ν = 2T
Answer: B
19. Amplitude of a sound wave is related to:
A. Pitch
B. Loudness
C. Frequency only
D. Speed only
Answer: B
20. A louder sound has:
A. Smaller amplitude
B. Larger amplitude
C. Smaller wavelength
D. Zero frequency
Answer: B
21. Pitch of sound depends on:
A. Amplitude
B. Speed
C. Frequency
D. Medium only
Answer: C
22. A high pitch sound has:
A. Low frequency
B. High frequency
C. Low amplitude
D. Large wavelength only
Answer: B
23. Human audible range is:
A. 0–100 Hz
B. 20 Hz–20 kHz
C. 200 Hz–2000 Hz
D. 50 Hz–5 kHz
Answer: B
24. Sound waves below 20 Hz are called:
A. Ultrasonic waves
B. Audible waves
C. Infrasonic waves
D. Radio waves
Answer: C
25. Sound waves above 20 kHz are:
A. Infrasonic
B. Ultrasonic
C. Audible
D. Seismic
Answer: B
26. Bats use ultrasonic waves for:
A. Photosynthesis
B. Echolocation
C. Respiration
D. Digestion
Answer: B
27. SONAR works on:
A. Refraction of sound
B. Reflection of sound
C. Dispersion of sound
D. Diffraction of sound
Answer: B
28. The phenomenon of repeated reflection of sound is:
A. Reverberation
B. Refraction
C. Interference
D. Resonance
Answer: A
29. Reflection of sound causing repetition is called:
A. Pitch
B. Echo
C. Timbre
D. Loudness
Answer: B
30. Minimum distance required to hear a distinct echo is approximately:
A. 5 m
B. 10 m
C. 17 m
D. 34 m
Answer: C
Assertion–Reason MCQs
31.
Assertion (A): Sound cannot travel in vacuum.
Reason (R): Sound requires a material medium.
A. Both A and R are true, and R explains A
B. Both A and R are true, but R does not explain A
C. A is true but R is false
D. A is false but R is true
Answer: A
32.
Assertion (A): Sound waves in air are longitudinal waves.
Reason (R): Air particles vibrate parallel to wave propagation.
A. Both A and R are true, and R explains A
B. Both A and R are true, but R does not explain A
C. A is true but R is false
D. A is false but R is true
Answer: A
33.
Assertion (A): Loud sounds have greater amplitude.
Reason (R): More energy is carried by larger amplitude waves.
A. Both A and R are true, and R explains A
B. Both A and R are true, but R does not explain A
C. A is true but R is false
D. A is false but R is true
Answer: A
34.
Assertion (A): Echoes are not heard in small rooms.
Reason (R): Reflected sound reaches too quickly to distinguish separately.
A. Both A and R are true, and R explains A
B. Both A and R are true, but R does not explain A
C. A is true but R is false
D. A is false but R is true
Answer: A
Case-Based MCQs
Case Study 1
A student struck a tuning fork and brought it near water.
35. Waves formed on water surface because:
A. Water evaporated
B. Tuning fork vibrated
C. Air pressure increased
D. Frequency decreased
Answer: B
36. Sound produced by tuning fork is due to:
A. Heating
B. Vibrations
C. Reflection
D. Magnetism
Answer: B
37. If the tuning fork stops vibrating:
A. Sound becomes louder
B. Sound stops
C. Frequency increases
D. Echo forms
Answer: B
Case Study 2
A naval ship uses SONAR to detect underwater objects.
38. SONAR uses:
A. Light waves
B. Radio waves
C. Ultrasonic waves
D. Infrared waves
Answer: C
39. SONAR works on:
A. Refraction
B. Reflection
C. Dispersion
D. Polarization
Answer: B
Competency-Based MCQs
40. A sound wave has frequency 50 Hz. Number of oscillations in 1 second is:
\nu=50\ \mathrm{Hz}
A. 25
B. 50
C. 100
D. 500
Answer: B
41. Time period of a wave having frequency 5 Hz is:
T=\frac{1}{\nu}=\frac{1}{5}=0.2\ s
A. 0.5 s
B. 0.2 s
C. 5 s
D. 2 s
Answer: B
42. If wavelength is 2 m and frequency is 100 Hz, speed of sound is:
v=\lambda\nu=2\times100=200\ \mathrm{m/s}
A. 50 m/s
B. 100 m/s
C. 200 m/s
D. 400 m/s
Answer: C
43. Which medium allows fastest propagation of sound?
A. Air
B. Vacuum
C. Water
D. Steel
Answer: D
44. A shrill sound has:
A. Low frequency
B. High frequency
C. Low amplitude
D. Low speed
Answer: B
45. Which animal can detect ultrasonic waves?
A. Cow
B. Bat
C. Elephant
D. Horse
Answer: B
46. Which waves are used in ultrasonography?
A. Infrasonic waves
B. Radio waves
C. Ultrasonic waves
D. Light waves
Answer: C
47. Reverberation can be reduced by:
A. Using smooth walls
B. Using curtains and soft surfaces
C. Increasing loudness
D. Removing furniture
Answer: B
48. If sound travels 1700 m in 5 s, speed is:
v=\frac{1700}{5}=340\ \mathrm{m/s}
A. 170 m/s
B. 340 m/s
C. 850 m/s
D. 34 m/s
Answer: B
49. The quality that distinguishes sounds from different instruments is:
A. Loudness
B. Pitch
C. Timbre
D. Intensity
Answer: C
50. Which statement BEST explains sound propagation?
A. Sound transfers matter from source to listener
B. Medium particles travel long distances with wave
C. Energy propagates through vibrations of medium particles
D. Sound propagates only in solids
Answer: C
