Here we are providing Class 9 Science Objective Chapter – 12 Sound because its very important for Class 9 students as we all know that every board exam question has MCQs so that students should practice these questions so that students can get good marks in board. Class 9 Science Objective Chapter – 12 Sound is an extremely important and its also a year in which students learn the fundamentals of concepts that help them lay a solid foundation for their higher education. Here we are providing in Class Class 9 Science Objective Chapter – 12 Sound 100+ questions so that students practice more and more. If you want class wise Notes Then Click Here
Class 9 Science Objective Chapter – 12 Sound
1. Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting
( A ) intensity of sound only
( B ) amplitude of sound only
( C ) frequency of the sitar string with the frequency of other musical instruments
( D ) loudness of sound
Ans – ( C )
2. The distance between a consecutive crest and trough is x. The wavelength of the wave is
( A ) 4x
( B ) x
( C ) x/2
( D ) 2x
Ans – ( D )
3. Sound can be transferred through
( A ) Solid
( B ) Liquid
( C ) Gases
( D ) All of these
Ans – ( D )
4. Before the main shock waves, the earthquake produces the characteristic sound waves which some animals like rhinoceros can hear. Can you guess the kind of sound waves produced here?
( A ) Infrasonic sounds
( B ) Ultrasonic sounds
( C ) Audible Sounds
( D ) None of these
Ans – ( A )
5. Sound wave is a
( A ) transverse wave
( B ) longitudinal wave
( C ) both a and b
( D ) None of these
Ans – ( A )
6. The SI unit of frequency is —
( A ) Hertz
( B ) Per second
( C ) Meter/ second
( D ) Both a) and b)
Ans – ( D )
7. When we change feeble sound to loud sound we increase its
( A ) frequency
( B ) amplitude
( C ) velocity
( D ) wavelength
Ans – ( B )
8. You can not talk to each other on the moon because
( A ) atmosphere is not present, that is, there is vacuum
( B ) you would not feel like talking
( C ) compressions and rarefactions can only travel on earth’s surface
( D ) gravity is 1/6th that on the earth
Ans – ( A )
9. Loudness or softness of a sound is depend on
( A ) Amplitude
( B ) Frequency
( C ) Type of a wave
( D ) None of these
Ans – ( A )
10. Sound waves are
( A ) magnetic waves
( B ) electric waves
( C ) electromagnetic waves
( D ) mechanical waves
Ans – ( D )
11. Sonic booms are caused by the combination of
( A ) supersonic speed and pressure variation.
( B ) infrasonic speed and pressure variation.
( C ) ultrasonic sound and pressure variation.
( D ) pressure variation only.
Ans – ( A )
12. Amplitude of the wave is depend on
( A ) Nature of wave
( B ) Force with which an object is made tovibrate
( C ) Displacement of the sound wave
( D ) Frequency of a wave
Ans – ( B )
13. In longitudinal waves, how does the particle of medium vibrate compared to the direction of propagation of wave?
( A ) Perpendicular
( B ) Parallel
( C ) At 45°
( D ) At 60°
Ans – ( B )
14. Note is a sound
( A ) of mixture of several frequencies
( B ) of mixture of two frequencies only
( C ) of a single frequency
( D ) always unpleasant to listen
Ans – ( C )
15. The sound waves in a medium are characterised by the
( A ) Linear motion of particles in the medium
( B ) Rotatory motion of particles in the medium
( C ) Oscillatory motion of particles in the medium
( D ) None of the above
Ans – ( C )
16.The speed of sound is greater in
( A ) Nickel
( B ) Ethanol
( C ) Air
( D ) Sulphur dioxide
Ans – ( A )
17. The sound can travel in air when
( A ) Particles of medium travel from one place to another
( B ) There is no moisture in the atmosphere
( C ) Disturbance travel from one place to another
( D ) Both particles as well as disturbance travel from one place to another
Ans – ( C )
18. Sound can travel through
( A ) gases only
( B ) vacuum only
( C ) gases and liquids only
( D ) solids, liquids and gases.
Ans – ( D )
19. Horns of the vehicles are based on the principle of
( A ) Echo
( B ) Multiple reflections of sound
( C ) Ultrasound waves
( D ) None of these
Ans – ( B )
20. A key of a mechanical piano struck gently and then struck again but mush harder this time. In the second case
( A ) sound will be louder but pitch will not be different
( B ) sound will be louder and pitch will also be higher
( C ) sound will be louder but pitch will be lower
( D ) both loudness and pitch will remain unaffected
Ans – ( A )
21. Children under age of 5 years can hear sound upto
( A ) 10 kHz
( B ) 20 2Hz
( C ) 25 kHz
( D ) 30 kHz
Ans – ( C )
22. The motion of the particles of a medium when a sound wave is passing through it is
( A ) translatory
( B ) random
( C ) rotatory
( D ) oscillatory
Ans – ( D )
23. For hearing a distinct sound, the time interval between the original sound and the reflected one must be at least
( A ) 1 s
( B ) 0.1 s
( C ) 2 s
( D ) 0.2 s
Ans – ( B )
24. Rhinoceroses communicate using
( A ) Ultrasound waves
( B ) Infrasound waves
( C ) Audible sound waves
( D ) All of the above
Ans – ( B )
25.The persistence of sound in an auditorium is the result of repeated reflections of sound and is called
( A ) reverberation
( B ) audible
( C ) distinct sound
( D ) reflection
Ans – ( A )
26. We can distinguish between a man’s voice and a woman’s voice of the same loudness even without seeing them. This is due to a characteristic of sound which measures the shrillness of sounds. Can you choose the correct unit of the quantity on which this characteristic of sound depends?
( A ) hertz
( B ) meter/second
( C ) meter
( D ) unitless
Ans – ( A )
27. The frequency of ultrasound waves is
( A ) Less than audible sound waves
( B ) Greater than audible sound waves
( C ) Equal to or less than sound waves
( D ) None of these
Ans – ( B )
28. Which of the following can produce longitudinal as well as transverse waves under different conditions?
( A ) Bats
( B ) Slinky
( C ) Tuning fork
( D ) None of these
Ans – ( B )
29. If the pendulum oscillate 78 times in one minute then the frequency of that pendulum will be—
( A ) 2 Hz
( B ) 1.5 Hz
( C ) 1.3 Hz
( D ) 1.2 Hz
Ans – ( C )
30. Infrasound can be heard by
( A ) dog
( B ) bat
( C ) rhinoceros
( D ) human beings
Ans – ( C )
31. The speed v, frequency υ, and wavelength λ, of sound are related by the equation
( A ) v = λυ
( B ) υ = λv
( C ) λ = υv
( D ) v = λ\υ
Ans – ( A )
32. An earthquake produces which kind of sound before the mainshock wave begins
( A ) ultrasound
( B ) infrasound
( C ) audible sound
( D ) None of the above
Ans – ( b )
33.Which of the following is carried by the waves from one place to another
( A ) Velocity
( B ) Work
( C ) Energy
( D ) Mass
Ans – ( C )
34. The upper frequency limit of the audible range of human hearing is about
( A ) 20 kHz
( B ) 2000 Hz
( C ) 2 kHz
( D ) 2,000,000 Hz
Ans – ( A )
35. Earthquake produces which kind of sound before the main shock wave begins
( A ) ultrasound
( B ) infrasound
( C ) audible sound
( D ) none of the above
Ans – ( A )
36. In gases a sound wave is
( A ) Longitudinal only
( B ) Transverse only
( C ) both A and B
( D ) None of these
Ans – ( A )
37. Which of the following vibrates when a musical note is produced by the cymbals in an orchestra ?
( A ) stretched strings
( B ) stretched membranes
( C ) metal plates
( D ) air columns
Ans – ( C )
38. The speed of sound is maximum in
( A ) solids
( B ) liquids
( C ) gases
( D ) All of these
Ans – ( a )
39. A body produces sound only if it is
( A ) Made of glass
( B ) Made of aluminium
( C ) Vibration
( D ) Made of iron
Ans – ( C )
40. The frequency of sound waves can be expressed in
( A ) Second
( B ) Cycle
( C ) Metre per second
( D ) Cycle per second
Ans – ( D )
41. Which one of the following does not consist of transverse waves ?
( A ) light emitted by a CFL
( B ) TV signals from a satellite
( C ) ripples on the surface of a pond
( D ) musical notes of an orchestra
Ans – ( D )
42. Our ears are sensitive to sound frequencies between
( A ) 20 Hz to 20 kHz
( B ) 2 Hz to 20 Hz
( C ) 20 kHz to 200 kHz
( D ) 2000 kHz to 20000 kHz
Ans – ( A )
43. The equipment (device) used for locating the position and distance of an object inside sea, using ultrasound is called–
( A ) Pukar
( B ) Upkar
( C ) Radar
( D ) Sonar
Ans – ( D )
44. If the speed of a wave is 380 m/s and its frequency is 1900 Hz, then the wavelength of the wave will be
( A ) 20 m
( B ) 0.2 m
( C ) 200 m
( D ) 2 m
Ans – ( C )
45. Human ear can hear–
( A ) audible sound
( B ) infra sound
( C ) ultra sound
( D ) all the above
Ans – ( A )
46. In SONAR, we use
( A ) ultrasonic waves
( B ) infrasonic waves
( C ) radio waves
( D ) audible sound waves
Ans – ( C )
47. Sound travels
( A ) slower in warm air than in cold air
( B ) faster in solids and liquids than in air
( C ) slower in water than air
( D ) none of these
Ans – ( B )
48. In which medium sound travels faster–
( A ) solid
( B ) liquid
( C ) gas
( D ) none of these
Ans – ( A )
49. On increasing the temperature, the speed of sound in air
( A ) Increases
( B ) Decreases
( C ) Does not change
( D ) First increases then becomes constant
Ans – ( A )
50. Sound is produced by _________objects.
( A ) fast moving
( B ) vibrating
( C ) stationary
( D ) rotating
Ans – ( B )
51. Pitch of high frequency sound is–
( A ) high
( B ) low
( C ) zero
( D ) infinite
Ans – ( A )
52. Loudness measures the sound energy reaching the ear per second and depends on the amplitude of the sound wave. What is the unit used to measure the loudness of sound?
( A ) hertz
( B ) decibel
( C ) meter/second
( D ) second
Ans – ( B )
53. A key of mechanical piano is first struck gently and then struck again but much harder this time. What kind of change in sound will you observe in the second case
( A ) Sound will be louder but the pitch will not be different
( B ) Sound will be louder and the pitch will also be higher
( C ) Sound will be louder but the pitch will be lower
( D ) Both loudness and pitch will remain unaffected
Ans – ( C )
54. Which of the following waves are produced by bats?
( A ) Infrasonic waves
( B ) Ultrasonic waves
( C ) Audible waves
( D ) All of these
Ans – ( B )
55. In case of transverse waves the particles of a medium vibrate
( A ) In the direction of wave propagation
( B ) Opposite to the direction of wave propagation
( C ) At the right angles to the direction of wave propagation
( D ) None of the above
Ans – ( C )
56. Maximum tolerable sound is
( A ) 0 dB
( B ) 10 dB
( C ) 60 dB
( D ) 120 dB
Ans – ( D )
57. The upper frequency limit of the audible range of human hearing is about
( A ) 20 kHz
( B ) 2000 Hz
( C ) 2 kHz
( D ) 2,000,000 Hz
Ans – ( A )
58. Sound travels in air if
( A ) particles of medium travel from one place to another
( B ) there is no moisture in the atmosphere
( C ) disturbance moves
( D ) both particles as well as disturbance travel from one place to another
Ans – ( D )
