# Class 10 Physics Chapter 2

Updated: 17 Dec 2023

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Class 10 Physics Chapter 2 introduces the concept of “Sound”. This is mainly chapter No. 11, “Sound”, of the book of Class 10.
This article consists of Notes, SLO Based Notes and MCQs of Physics, which cover your course, board papers and clear your Physics concept for different types of tests.

## Class 10 Physics Chapter 2 Notes

### Sound

Class 10 Physics Chapter No. 11 Notes

### SLO Base Notes

Class 10 Physics Chapter 11 SLO Base Notes

## Class 10 Physics Chapter 2 MCQs

1. The sensation felt by the human ear is called:
(a) Vibration
(b) Sound
(c) Volume
(d) Acoustic sensation

Sound

2. What is the primary medium through which sound travels?
(a) Vacuum
(b) Solid
(c) Liquid
(d) Gas

Gas

3. Which type of waves do sound waves belong to?
(a) Transverse waves
(b) Electromagnetic waves
(c) Longitudinal waves
(d) Surface waves

Longitudinal waves

4. How is a sound wave created?
(a) By light waves
(b) By a vibrating object
(c) By electric current
(d) By magnetic fields

By a vibrating object

5. What is a region of high molecular density and high air pressure called in a sound wave?
(a) Compression
(b) Rarefaction
(c) Refraction
(d) Diffraction

Compression

6. What is a region of low molecular density and low air pressure called in a sound wave?
(a) Compression
(b) Rarefaction
(c) Refraction
(d) Diffraction

Rarefaction

7. In what type of medium can sound be transmitted?
(a) Vacuum only
(b) Liquid only
(c) Solid only
(d) Gas, liquid, or solid

Gas, liquid, or solid

8. Sound waves cannot travel through:
(a) Air
(b) Vacuum
(c) Water
(d) Glass

Vacuum

9. In which medium does sound typically travel faster compared to the others?
(a) Air
(b) Water
(c) Solid
(d) Vacuum

Solid

10. In which medium does sound typically travel slower compared to the others?
(a) Air
(b) Water
(c) Solid
(d) None of these

Air

11. What is the biological organ responsible for converting sound waves into the perception of hearing?
(a) Nose
(b) Eye
(c) Ear
(d) Tongue

Ear

12. How do microphones detect sound?
(a) By converting it into light signals
(b) By converting it into mechanical energy
(c) By converting it into electrical signals
(d) By converting it into heat energy

By converting it into electrical signals

13. What is the term for the awareness of sound through the senses?
(a) Reflection
(b) Oscillation
(c) Acoustics
(d) Perception

Perception

14. How do persons with hearing impairment detect sound?
(a) Through their ears
(b) By using artificial hearing devices
(d) None of these

By using artificial hearing devices

15. What distinguishes between shrill and grave sound:
(a) Pitch
(b) Volume
(c) Loudness
(d) Quality

Pitch

16. The pitch of sound depends on:
(a) Amplitude of the sound wave
(b) Phase of the sound wave
(c) Frequency of the sound wave
(d) Speed of sound

Frequency of the sound wave

17. What will be the pitch of sound when the frequency is high:
(a) The pitch will be low
(b) The pitch will be moderate
(c) The pitch will be high
(d) The pitch will be unpredictable

The pitch will be high

18. What will be the pitch of sound when the frequency is low:
(a) The pitch will be low
(b) The pitch will be moderate
(c) The pitch will be high
(d) The pitch will be unpredictable

The pitch will be low

19. A high-pitched sound is called:
(a) Shrill sound
(b) Grave sound
(c) Loud sound
(d) None of these

Shrill sound

20. A low-pitched sound is called:
(a) Shrill sound
(b) Grave sound
(c) Loud sound
(d) None of these

Grave sound

21. Which of the following sounds is typically associated with a low pitch?
(a) Women singing
(b) Birds chirping
(c) Dogs barking
(d) Cats meowing

Dogs barking

22. Which of the following sounds is typically associated with a high pitch?
(a) Men singing
(b) Frogs croaking
(c) Lions roaring
(d) Birds chirping

Birds chirping

23. Pitch in sound can be compared to what property in light?
(a) Brightness
(b) Color
(c) Intensity
(d) Transparency

Color

24. What factor primarily determines the loudness of a sound?
(a) Frequency of the sound wave
(b) Speed of sound
(c) Amplitude of the sound wave
(d) Shape of the sound wave

Amplitude of the sound wave

25. How does the area of a vibrating body relate to the loudness of the sound it produces?
(a) Smaller area leads to louder sound
(b) Larger area leads to louder sound
(c) Area has no effect on loudness
(d) None of these

Larger area leads to louder sound

26. What effect does distance from the source of sound have on loudness?
(a) Closer distance leads to louder sound
(b) Farther distance leads to louder sound
(c) Distance has no effect on loudness
(d) None of these

Closer distance leads to louder sound

27. How does the material through which sound is traveling affect the amplitude of the sound wave?
(a) It does not affect the amplitude
(b) It decreases the amplitude in all materials
(c) Amplitude is different in different materials
(d) It increases the amplitude in all materials

Amplitude is different in different materials

28. The property of sound by which two sounds of the same loudness and pitch are distinguished from each other is called
(a) Loudness of sound
(b) Pitch of sound
(c) Amplitude of sound
(d) Quality of sound

Quality of sound

29. When comparing the sound from a piano and a flute, what distinguishes them?
(a) Loudness
(b) Pitch
(c) Quality or timbre
(d) Frequency

Quality or timbre

30. The measure of sound energy reaching an area in a unit time is called:
(a) Amplitude
(b) Frequency
(c) Intensity
(d) Loudness

Intensity

31. Intensity of sound is represented by:
(a) I
(b) L
(c) F
(d) P

I

32. What is the mathematical expression for the intensity of sound?
(a) I = \frac{E}{A}

(b) I = \frac{P}{A}

(c) I = \frac{A}{P}

(d) I = E \times A

I = \frac{P}{A}

33. What is the SI unit of intensity of sound?
(a) Hertz (Hz)
(b) Decibel (dB)
(c) Watt per square meter (W/m^2)
(d) Watt (W)

Watt per square meter (W/m^2)

34. 1 Pico watt per square meter is equal to:
(a) 1 \times 10^{3} W/m^2
(b) 1 \times 10^{-6} W/m^2
(c) 1 \times 10^{-12} W/m^2
(d) 1 \times 10^6 W/m^2

1 \times 10^{-12} W/m^2

35. What property of sound depends on the characteristics of a person’s ears?
(a) Intensity
(b) Loudness
(c) Frequency
(d) Amplitude

Loudness

36. Which of the following is an objective property of sound waves?
(a) Intensity
(b) Loudness
(c) Pitch
(d) Frequency

Intensity

37. The range of intensity that the average human ear can detect:
(a) 10^5 W/m^2 \ to \ 10^6 W/m^2

(b) 10^{-5} W/m^2 \ to \ 10^6 W/m^2

(c) 10^{-12} W/m^2 \ to \ 1 W/m^2

(d) 10^{-10} W/m^2 \ to \ 10^{-9} W/m^2

10^{-12} W/m^2 \ to \ 1 W/m^2

38. What is the difference between the loudness of two sounds represented by (L-L_o) ?
(a) Intensity level
(b) Decibel unit
(c) Sound frequency
(d) Sound wavelength

Intensity level

39. Intensity level is represented by:
(a) I
(b) L
(c) W
(d) \beta \ (beta)

\beta \ (beta)

40. What is the mathematical relationship between loudness (L) and sound intensity (I) in terms of the Bel unit?
(a) L = k \ \log (I)
(b) L = \log (I)
(c) L = \ log (kI)
(d) L = \frac{I}{k}

L = k \log (I)

41. If the intensity of a sound is ten times greater than the intensity of the faintest audible sound, what is the intensity level of that sound in Bels?
(a) 10 bels
(b) 1 bel
(c) 0.1 bel
(d) 100 bels

1 bel

42. How many decibels are in 1 bel?
(a) 10 decibels
(b) 100 decibels
(c) 0.1 decibels
(d) 1 decibel

10 decibels

43. What is the unit of intensity level used to quantify sound intensity differences?
(a) Hertz (Hz)
(b) Hertz (Hz)
(c) Watt (W)
(d) Decibel (dB)

Decibel (dB)

44. What is the intensity level (in decibels) of normal breathing?
(a) 10 dB
(b) 20 dB
(c) 30 dB
(d) 40 dB

10 dB

45. At what intensity level (in decibels) does a military jet take off?
(a) 110 dB
(b) 120 dB
(c) 130 dB
(d) 150 dB

150 dB

46. What is the threshold of pain in terms of intensity level (in decibels)?
(a) 140 dB
(b) 160 dB
(c) 170 dB
(d) 200 dB

140 dB

47. What does a 56.0 dB sound represent in terms of its intensity compared to a 53.0 dB sound?
(a) It is half as intense
(b) It is twice as intense
(c) It is one-tenth as intense
(d) It is ten times as intense

It is twice as intense

48. If a sound has an intensity level of 97.0 dB, how does its intensity compare to a 100 dB sound?
(a) It is half as intense
(b) It is twice as intense
(c) It is one-tenth as intense
(d) It is ten times as intense

It is half as intense

49. The intensity of a sound wave increases by 1000 \ W/m^2 . What is this increase equal to in decibels?
(a) 10 dB
(b) 20 dB
(c) 30 dB
(d) 40 dB

30 dB

50. What is the term for the distance covered by a sound wave in unit time?
(a) Wavelength
(b) Amplitude
(c) Frequency
(d) Speed

Speed

51. How is the speed of sound represented in equations?
(a) S
(b) V
(c) F
(d) L

V

52. What is the speed of sound in air at 20 {}^oC ?
(a) 343 \ m/s
(b) 5104 \ m/s
(c) 332 \ m/s
(d) 258 \ m/s

343 \ m/s

53. In which medium does sound travel most rapidly?
(a) Solid
(b) Liquid
(c) Gas
(d) All of these

Solid

54. In which medium does sound travel slowest?
(a) Solid
(b) Liquid
(c) Gas
(d) All of these

Gas

55. What is the speed of sound in aluminum?
(a) 5104 \ m/s
(b) 4110 \ m/s
(c) 1493 \ m/s
(d) 1270 \ m/s

5104 \ m/s

56. How many times is the speed of sound greater in water than in air?
(a) Twice
(b) Five times
(c) It’s the same
(d) It’s slower in water

Five times

57. What properties of air affect the speed of sound?
(a) Color and odor
(b) Altitude and pressure
(c) Temperature and compressibility
(d) Altitude and humidity

Temperature and compressibility

58. At a temperature of 0 {}^oC and a pressure of 101 \ kPa , what is the speed of sound in dry air?
(a) 0.6 \ m/s
(b) 331 \ m/s
(c) 343 \ m/s
(d) 101 \ m/s

331 \ m/s

59. How much does the speed of sound in air increase for each 1 {}^oC rise in temperature, approximately?
(a) 0.6 \ m/s
(b) 1 \ m/s
(c) 10 \ m/s
(d) 100 \ m/s

0.6 \ m/s

60. What happens to the speed of sound in air when the frequency of a sound wave is doubled?
(a) It decreases
(b) It increases
(c) It remains the same
(d) It becomes inaudible

It remains the same

61. What happens to the speed of sound in air when the wavelength of a sound wave is doubled?
(a) It decreases
(b) It increases
(c) It remains the same
(d) It becomes inaudible

It remains the same

62. If the temperature rises from 20 \ {}^oC \ to \ 30 {}^oC , approximately how much does the speed of sound in air change?
(a) It decreases by 6 m/s
(b) It increases by 6 m/s
(c) It remains the same
(d) It becomes zero

It increases by 6 m/s

63. What do we call the bouncing back of sound waves when they strike a surface?
(a) Absorption of sound
(b) Transmission of sound
(c) Reflection of sound
(d) Diffraction of sound

Reflection of sound

64. What is the term for sound due to multiple reflections in a small room?
(a) Refraction
(b) Echo
(c) Absorption
(d) Reverberation

Reverberation

65. What is the term for a reflected sound that can be distinguished from the original sound?
(a) Refraction
(b) Echo
(c) Absorption
(d) Reverberation

Echo

66. How long does it take for a reflected sound to be perceived as an echo by the human ear?
(a) 0.01 seconds
(b) 1 second
(c) 0.10 seconds
(d) 10 seconds

0.10 seconds

67. Besides the repetition of words, what can echoes are used to estimate?
(a) Temperature
(b) Distance of an object and velocity of sound
(c) Time of day
(d) Humidity

Distance of an object and velocity of sound

68. Minimum echo distance is reduced in _____________.
(a) Summer
(b) Spring
(c) Winter
(d) Space

Winter

69. If the speed of sound is 343 m/s and the sound reaches the ear in 0.15 seconds, what is the calculated distance to the source?
(a) 25.7 meters
(b) 51.75 meters
(c) 100 meters
(d) 343 meters

25.7 meters

70. What is acoustics the study of?
(a) Light and optics
(b) Waves, vibrations, and sound
(c) Geology and rocks
(d) Heat and thermodynamics

Waves, vibrations, and sound

71. How do rugs and furniture affect the acoustics of a room?
(a) They make the room sound dull
(b) They increase the sound level
(c) They create echoes
(d) They have no effect on acoustics

They make the room sound dull

72. What is the term for the balance between reverberation and absorption in room acoustics?
(a) Reflection
(b) Resonance
(c) Diffraction
(d) Architectural acoustics

Architectural acoustics

73. In architectural acoustics, what do parabolic surfaces do?
(a) Absorb sound
(b) Reflect sound
(c) Focus sound
(d) Disperse sound

Focus sound

74. What effect does a flat surface typically have on sound in architectural acoustics?
(a) Absorbs sound
(b) Reflects sound
(c) Focuses sound
(d) Scatters sound

Reflects sound

75. What is the primary characteristic of porous surfaces in acoustics?
(a) They absorb sound
(b) They reflect sound
(c) They focus sound
(d) They generate echoes

They absorb sound

76. How do jagged surfaces influence sound in architectural acoustics?
(a) They absorb sound
(b) They reflect sound
(c) They disperse sound
(d) They focus sound

They disperse sound

77. What is the primary purpose of acoustic protection?
(a) To enhance physical health
(b) To minimize stress levels
(c) To protect structures against vibrations
(d) To control noise during construction

To enhance physical health

78. Who, besides humans, can be affected by high noise and sound levels?
(a) Plants
(b) Insects
(c) Animals and birds
(d) Rocks and minerals

Animals and birds

79. Why might acoustic protection be required during construction and development activities?
(a) To increase noise levels
(b) To enhance structural stability
(c) To improve communication
(d) To control and reduce noise

To control and reduce noise

80. What is the term for excessive displeasing sound that disrupts the balance or activity of humans or other living things?
(a) Sound pollution
(b) Noise pollution
(c) Sonic disruption
(d) Acoustic imbalance

Noise pollution

81. At what sound level can prolonged exposure begin to damage hearing irreversibly?
(a) 60 dB
(b) 85 dB
(c) 100 dB
(d) 120 dB

85 dB

82. What sound level is capable of causing immediate damage?
(a) 60 dB
(b) 85 dB
(c) 100 dB
(d) 120 dB

120 dB

83. According to the World Health Organization, what is the recommended noise level during sleep to avoid disruption?
(a) 20 dB
(b) 35 dB
(c) 50 dB
(d) 75 dB

35 dB

84. Which classification of sound includes frequencies in the range of 20 Hz to 20,000 Hz?
(a) Ultrasonic
(b) Infrasonic
(c) Audible
(d) Supersonic

Audible

85. What is the upper limit of the audible frequency range for a healthy young person?
(a) 5,000 Hz
(b) 20,000 Hz
(c) 10,000 Hz
(d) 30,000 Hz

20,000 Hz

86. What is the term for sound frequencies lower than 20 Hz?
(a) Ultrasonic
(b) Infrasonic
(c) Audible
(d) Supersonic

Infrasonic

87. Which animals are known to use infra-sound for communication over long distances?
(a) Birds and dolphins
(b) Whales, elephants
(c) Tigers and lions
(d) Fish and frogs

Whales, elephants

88. What is the possible maximum range of communication for elephants using infra-sound?
(a) 1 km
(b) 5 km
(c) 10 km
(d) 20 km

10 km

89. What is the term for sound frequencies greater than 20 kHz?
(a) Ultrasonic
(b) Infrasonic
(c) Audible
(d) Supersonic

Ultrasonic

90. Which animals use ultrasonic ranging (echolocation) to detect their prey?
(a) Lions and tigers
(b) Bats and whales
(c) Eagles and hawks
(d) Frogs and turtles

Bats and whales

91. What is the frequency range of ultrasonic signals that bats can produce for echolocation?
(a) Up to 10 kHz
(b) Around 50 kHz
(c) Beyond 100 kHz, possibly up to 200 kHz
(d) Exactly 300 kHz

Beyond 100 kHz, possibly up to 200 kHz

92. What is the common use of ultrasonic sensors in automatic door openers?
(a) Measuring temperature
(b) Detecting intruders
(c) Playing music
(d) Lighting up the room

Detecting intruders

93. How is ultrasonic testing commonly used in nondestructive testing?
(a) To measure temperature
(b) To communicate underwater
(c) To find flaws in materials and measure thickness
(d) To diagnose medical conditions

To find flaws in materials and measure thickness

94. What does SONAR stand for?
(c) Sound Only for Navigational Accuracy and Range

95. What is responsible for most of the cleansing action in ultrasonic cleaners?
(a) High-pressure water jets
(b) Magnetic fields
(c) Cavitation
(d) Ultraviolet (UV) light