# AP 9th Physical Science Mock Test 2021 For Chapter 10 – “Sound” Online Practice Test

1. A body produces sound only if it is
2. Sound waves cannot pass through
3. In which of the following media will sound travel faster.................
4. Sound waves having the following frequency audible by a human beings are
5. The maximum displacement of a particle in wave motion is called
6. The SI unit of amplitude of motion is
7. Hz is the unit of
8. The separation between two consecutive compressions are
9. The reciprocal of frequency is
10. The lowest audible frequency for a human being is about
11. The product of time period and frequency is
12. Sound waves are
13. Echo is a phenomenon of
14. Waves transfer .... from one place to another
15. Sound wave can travel through ......................
16. Generally ceiling of concrete halls are
17. ............ is the medical instrument used for listening heart beat
18. A refraction of sound , arriving at the listener in less than 0.1 sec after direct round is called
19. The value of resistance of sound
20. A refraction of sound , arriving at the listener in more than 0.1 sec after direct round is called
21. The minimum distance for hearing an echo between listener and reflecting surface is ..................
22. Rhinoceroses communicate using infrasonic sounds of frequency around
23. The waves produced in a spring - mass device
24. The region of minimum density in a medium is called
25. If time period is 't' and the number of oscillations per second is (v) then v is
26. The velocity of sound in vacuum is
27. One kilohertz is
28. The range hearing by an ordinary man is
29. The degree of sensation to produced on the ear by sound is called
30. The relation among the velocity , frequency and wavelength is
31. The maximum displacement in a transverse wave occurs at
32. Identify the wrong pair among them
33. Velocity of sound is very high in
34. Assume that the atmosphere is absent on earth then the velocity of the sound wave in this situation is
35. The wave which consist of a set of compression and rarefaction
36. Sound travels in a form of
37. Cleaning can be done more efficiently by
38. Choose the correct match
1. Unit of frequency                       ( ) a. 20 Hz - 20 kHz
2. Range of hearing                        ( ) b. Hertz
3. Works on multiple reflections ( ) c. Ultrasonics
4. Used in micro surgery               ( ) d. Stethoscope
39. Choose the correct match
1. The minimum distance to hear echo  ( ) a. Compression
2. Persistence of learning is                      ( ) b. Rarefaction
3. Region of inversed pressure                 ( ) c. 16.5 m
4. Region of decreased pressure               ( ) d. sec
40. SI unit of frequency
41. Speed of sound wave =
42. Holes can be drilled in metaplates by use
43. The instrument used to produce sound of known frequency
44. Find the time period of the waves whose frequency is 500 Hz
45. In a certain gas , a source produces 40,000 compressions and 40,000 rarefaction pulses in 1 sec. when the second compression pulse is produced; the first is 1 cm away from the source . Calculate the wave speed ?
46. An echo is heard after 0.8 s , when a boy fires a cracker , 132 m away from a tall building . Calculate the speed of sound ?
47. A research team sends a sonar signal to confirm the depth of a sea . They heard an echo after 6s. Find the depth of the sea , if the speed of sound in sea water is 1500 m/s ?
48. A man is lying on the floor of a large , empty hemispherical hall , in such a way that his head at the centre of the hall . He shouts "Hello!" and hears the echo of his voice after 0.2 sec . What is the radius of the hall ?(Speed of sound in air = 340 m/s)
49. A sound wave travels at a speed of 340 m/s . If its wavelength is 2cm , What is the frequency of the wave ? will it be in the audible range ?
50. Find the period of source of a sound wave whose frequency is 400 Hz ?
51. When we say sound travels in a medium it is
52. A sound wave consists of
53. Hertz stands for oscillations per
54. When we increase the loudness of sound of a TV , the property of sound that changes is
55. The characteristics of the sound that describes how the brain interprets the frequency of sound is called
56. In a stethoscope , sound of heart beats travel through stethoscope tube
57. Name the following
58. Which of the following are not a correct statement about tuning fork ?
59. Mass per unit volume of the medium is defined as
60. The high region of density of particles in the medium during propagation of sound is called
61. The region of low density of particles in the medium during propagation of sound is called
62. In transverse waves , the particles of the medium which have maximum displacement in the positive y-direction is called
63. In transverse waves , the particles of the medium which have maximum displacement in the negative y-direction is called
64. If the particles of the medium move to and fro along the direction of the propagation of the wave , the waves are called
65. If the particles of the medium vibrate in a direction perpendicular to the direction of propagation of wave , the waves are called
66. The force applied per unit area is called
67. Density d=
68. Pressure p =
69. The distance between two consecutive rarefaction is called
70. What
71. The maximum displacement of the medium particle from their mean position of wave is
72. The number of waves produced per second is called
73. The number of oscillations of density of medium at a place per unit time is called
74. 'A' stands for
75. .................. is a form of mechanical energy which produces sensation of hearing
76. ................... is defined as the degree of sensation produced in the ear
77. Industrial application of ultrasonics waves are
78. Medical application of ultrasounds
79. SONAR stands for
80. Name the device used for detect the distance of objects under water by means of reflected ultrasonic waves
81. SONAR consists the
82. Ultrasounds are used in
83. Now-a-days ................. is used instead of old X-ray
84. Ultrasonography is used to
85. Holes can also be drilled using ultrasonic vibrations produced in a metallic rod , called a
86. The following is done by
87. Sound of frequency less than 20 Hz is known as
88.  Sound of frequency greater than 20 Hz is known as
89. We say Ultrasonic sound when sound frequency is
90. We say Infrasonic sound when sound frequency is
91. patient's heartbeat reaches the doctor's ears by multiple reflection using the following
92. There some characteristics by which we can distinguish a musical note from other,they are
93. R: Sound of mosquito is shrill while sound of lion is growl
Q: Female voice is shriller than male voice
94. Which of the following are not a vector ?
95. Symbol for frequency
96. SI unit for Pressure
97. Metre is SI unit for
98. is symbol for
99. Match the following with their symbol

a. Amplitude   ( ) p. T
b. Frequency   ( ) q. A
c. Time             ( ) r. n
100. The following consists