MCQOPTIONS
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MCQOPTIONS
This section includes 114 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Two strings X and Y of a sitar produce a beat frequency 4 Hz. When the tension of the string Y is slightly increased the beat frequency is found to be 2 Hz. If the frequency of X is 300 Hz, then the original frequency of Y was [UPSEAT 2000] |
| A. | 296 Hz |
| B. | 298 Hz |
| C. | Greater than the velocity of sound |
| D. | 304 Hz |
| Answer» B. 298 Hz | |
| 52. |
A tuning fork of known frequency 256 Hz makes 5 beats per second with the vibrating string of a piano. The beat frequency decreases to 2 beats per second when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was [AIEEE 2003] |
| A. | 256 + 5 Hz |
| B. | 256 + 2Hz |
| C. | 750 Hz |
| D. | 256 ? 5Hz |
| Answer» E. | |
| 53. |
It is possible to hear beats from the two vibrating sources of frequency [UPSEAT 2001] |
| A. | 100 Hz and 150 Hz |
| B. | 20 Hz and 25 Hz |
| C. | 7 m/s |
| D. | 1000 Hz and 1500 Hz |
| Answer» C. 7 m/s | |
| 54. |
A tuning fork gives 4 beats with 50 cm length of a sonometer wire. If the length of the wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is [MP PMT 2001] |
| A. | 396 |
| B. | 400 |
| C. | 300 |
| D. | 384 |
| Answer» B. 400 | |
| 55. |
On sounding tuning fork A with another tuning fork B of frequency 384 Hz, 6 beats are produced per second. After loading the prongs of A with some wax and then sounding it again with B, 4 beats are produced per second. What is the frequency of the tuning fork A [MP PMT 2000] |
| A. | 388 Hz |
| B. | 380 Hz |
| C. | \[m=2\,kg\] |
| D. | 390 Hz |
| Answer» E. | |
| 56. |
The wavelengths of two waves are 50 and 51 cm respectively. If the temperature of the room is 20oC, then what will be the number of beats produced per second by these waves, when the speed of sound at 0oC is 332 m/sec [UPSEAT 1999] |
| A. | 14 |
| B. | 10 |
| C. | 0.6 m |
| D. | None of these |
| Answer» B. 10 | |
| 57. |
Beats are produced by two waves \[{{y}_{1}}=a\sin 1000\,\pi t,\] \[{{y}_{2}}=a\sin 998\pi t\] The number of beats heard/sec is [KCET 1998] |
| A. | 0 |
| B. | 2 |
| C. | \[n=5,\] \[{{f}_{2}}=\frac{5}{4}{{f}_{1}}\] |
| D. | 4 |
| Answer» D. 4 | |
| 58. |
An unknown frequency x produces 8 beats per seconds with a frequency of 250 Hz and 12 beats with 270 Hz source, then x is [CPMT 1997; KCET 2000] |
| A. | 258 Hz |
| B. | 242 Hz |
| C. | 180 |
| D. | 282 Hz |
| Answer» B. 242 Hz | |
| 59. |
Beats are the result of [CPMT 1971; J & K CET 2002] |
| A. | Diffraction |
| B. | Destructive interference |
| C. | 84 Hz |
| D. | Superposition of two waves of nearly equal frequency |
| Answer» E. | |
| 60. |
Two adjacent piano keys are struck simultaneously. The notes emitted by them have frequencies \[{{n}_{1}}\] and \[{{n}_{2}}\]. The number of beats heard per second is [CPMT 1974, 78; CBSE PMT 1993] |
| A. | \[\frac{1}{2}({{n}_{1}}-{{n}_{2}})\] |
| B. | \[\frac{1}{2}({{n}_{1}}+{{n}_{2}})\] |
| C. | 8 |
| D. | \[2\,({{n}_{1}}-{{n}_{2}})\] |
| Answer» D. \[2\,({{n}_{1}}-{{n}_{2}})\] | |
| 61. |
A tuning fork of frequency 100 when sounded together with another tuning fork of unknown frequency produces 2 beats per second. On loading the tuning fork whose frequency is not known and sounded together with a tuning fork of frequency 100 produces one beat, then the frequency of the other tuning fork is [NCERT 1977] |
| A. | 102 |
| B. | 98 |
| C. | \[I={{I}_{0}}\] |
| D. | 101 |
| Answer» B. 98 | |
| 62. |
Two tuning forks, A and B, give 4 beats per second when sounded together. The frequency of A is 320 Hz. When some wax is added to B and it is sounded with A, 4 beats per second are again heard. The frequency of B is [MP PMT 1997] |
| A. | 312 Hz |
| B. | 316 Hz |
| C. | Displacement |
| D. | 328 Hz |
| Answer» D. 328 Hz | |
| 63. |
Two tuning forks A and B give 4 beats per second. The frequency of A is 256 Hz. On loading B slightly, we get 5 beats in 2 seconds. The frequency of B after loading is [Haryana CEE 1996] |
| A. | 253.5 Hz |
| B. | 258.5 Hz |
| C. | Amplitude A, frequency \[2n\] and wavelength \[2\lambda \] |
| D. | 252 Hz |
| Answer» D. 252 Hz | |
| 64. |
A tuning fork A of frequency 200 Hz is sounded with fork B, the number of beats per second is 5. By putting some wax on A, the number of beats increases to 8. The frequency of fork B is [MP PMT 1996] |
| A. | 200 Hz |
| B. | 195 Hz |
| C. | 1 : 1 |
| D. | 205 Hz |
| Answer» E. | |
| 65. |
Speed of sound in mercury at a certain temperature is 1450 m/s. Given the density of mercury as 13.6 ´ 103 kg / m3, the bulk modulus for mercury is [JIPMER 2000] |
| A. | 2.86 ´1010 N/m3 |
| B. | 3.86 ´1010 N/m3 |
| C. | \[\sqrt{8}\] |
| D. | 5.86 ´1010 N/m3 |
| Answer» B. 3.86 ´1010 N/m3 | |
| 66. |
A wavelength 0.60 cm is produced in air and it travels at a speed of 300 ms?1. It will be an [UPSEAT 2000] |
| A. | Audible wave |
| B. | Infrasonic wave |
| C. | 560 Hz |
| D. | None of the above |
| Answer» D. None of the above | |
| 67. |
The intensity of sound increases at night due to [CPMT 2000] |
| A. | Increase in density of air |
| B. | Decreases in density of air |
| C. | 0.4m |
| D. | None of these |
| Answer» B. Decreases in density of air | |
| 68. |
A wave of frequency 500 Hz has velocity 360 m/sec. The distance between two nearest points 60° out of phase, is [NCERT 1979; MP PET 1989; JIPMER 1997; RPMT 2002, 03; CPMT 1979, 90, 2003; BCECE 2005] |
| A. | 0.6 cm |
| B. | 12 cm |
| C. | 6 |
| D. | 120 cm |
| Answer» C. 6 | |
| 69. |
What is the phase difference between two successive crests in the wave [RPMT 2001, 02; MH CET 2004] |
| A. | p |
| B. | p/2 |
| C. | 289 Hz |
| D. | 4p |
| Answer» D. 4p | |
| 70. |
Which of the following is not the transverse wave [AFMC 1999; BHU 2001] |
| A. | X-rays |
| B. | \[\gamma \]-rays |
| C. | 1 sec |
| D. | Sound wave in a gas |
| Answer» E. | |
| 71. |
The waves in which the particles of the medium vibrate in a direction perpendicular to the direction of wave motion is known as [EAMCT 1981; AIIMS 1998; DPMT 2000] |
| A. | Transverse wave |
| B. | Longitudinal waves |
| C. | 343 |
| D. | None of these |
| Answer» B. Longitudinal waves | |
| 72. |
Sound travels in rocks in the form of [NCERT 1968] |
| A. | Longitudinal elastic waves only |
| B. | Transverse elastic waves only |
| C. | p/2 |
| D. | Non-elastic waves |
| Answer» D. Non-elastic waves | |
| 73. |
Water waves are [EAMCET 1979; AIIMS 2004] |
| A. | Longitudinal |
| B. | Transverse |
| C. | 216 Hz |
| D. | Neither longitudinal nor transverse |
| Answer» D. Neither longitudinal nor transverse | |
| 74. |
An underwater sonar source operating at a frequency of 60 KHz directs its beam towards the surface. If the velocity of sound in air is 330 m/s, the wavelength and frequency of waves in air are: [DPMT 2004] |
| A. | 5.5 mm, 60 KHz |
| B. | 330 m, 60 KHz |
| C. | Velocity |
| D. | 5.5 mm, 80 KHz |
| Answer» B. 330 m, 60 KHz | |
| 75. |
If the temperature of the atmosphere is increased the following character of the sound wave is effected [AFMC 2004] |
| A. | Amplitude |
| B. | Frequency |
| C. | 3 |
| D. | Wavelength |
| Answer» D. Wavelength | |
| 76. |
When a sound wave of frequency 300 Hz passes through a medium the maximum displacement of a particle of the medium is 0.1 cm. The maximum velocity of the particle is equal to [MNR 1992; UPSEAT 1998, 2000; RPMT 2002; Pb. PET 2004] |
| A. | 60 p cm/sec |
| B. | 30 p cm/sec |
| C. | Remains same |
| D. | 60 cm/sec |
| Answer» B. 30 p cm/sec | |
| 77. |
A source of sound of frequency 600 Hz is placed inside water. The speed of sound in water is 1500 m/s and in air is 300 m/s. The frequency of sound recorded by an observer who is standing in air is [IIT-JEE Screening 2004] |
| A. | 200 Hz |
| B. | 3000 Hz |
| C. | 302 Hz |
| D. | 600 Hz |
| Answer» E. | |
| 78. |
A man sets his watch by a whistle that is 2 km away. How much will his watch be in error. (speed of sound in air 330 m/sec) [MP PET 1991] |
| A. | 3 seconds fast |
| B. | 3 seconds slow |
| C. | 256 ? 2 Hz |
| D. | 6 seconds slow |
| Answer» E. | |
| 79. |
A tuning fork makes 256 vibrations per second in air. When the velocity of sound is 330 m/s, then wavelength of the tone emitted is [KCET 1994; AFMC 1998; MH CET 1999; CBSE PMT 1999] |
| A. | 0.56 m |
| B. | 0.89 m |
| C. | 400 Hz and 500 Hz |
| D. | 1.29 m |
| Answer» E. | |
| 80. |
A man, standing between two cliffs, claps his hands and starts hearing a series of echoes at intervals of one second. If the speed of sound in air is 340 ms-1, the distance between the cliffs is [KCET 2004] |
| A. | 340 m |
| B. | 1620 m |
| C. | 404 |
| D. | 1700 m |
| Answer» B. 1620 m | |
| 81. |
If vm is the velocity of sound in moist air, vd is the velocity of sound in dry air, under identical conditions of pressure and temperature [KCET 2002, 03] |
| A. | vm > vd |
| B. | vm < vd |
| C. | 378 Hz |
| D. | vmvd = 1 |
| Answer» B. vm < vd | |
| 82. |
It takes 2.0 seconds for a sound wave to travel between two fixed points when the day temperature is \[{{10}^{o}}\]C. If the temperature rise to \[{{30}^{o}}\]C the sound wave travels between the same fixed parts in [Orissa JEE 2003] |
| A. | 1.9 sec |
| B. | 2.0 sec |
| C. | 24 |
| D. | 2.2 sec |
| Answer» B. 2.0 sec | |
| 83. |
Velocity of sound measured in hydrogen and oxygen gas at a given temperature will be in the ratio [RPET 2001; UPSEAT 2001; KCET 2002, 05] |
| A. | 1 : 4 |
| B. | 4 : 1 |
| C. | 1 |
| D. | 1 : 1 |
| Answer» C. 1 | |
| 84. |
If wavelength of a wave is \[\lambda =6000{AA}.\] Then wave number will be [MH CET 2002] |
| A. | \[166\times {{10}^{3}}\] m?1 |
| B. | \[16.6\times {{10}^{-1}}\] m?1 |
| C. | 262 Hz |
| D. | \[1.66\times {{10}^{7}}\] m?1 |
| Answer» D. \[1.66\times {{10}^{7}}\] m?1 | |
| 85. |
The temperature at which the speed of sound in air becomes double of its value at \[{{0}^{o}}C\] is [AIEEE 2002] |
| A. | 273K |
| B. | 546K |
| C. | Constructive and destructive interference |
| D. | 0K |
| Answer» D. 0K | |
| 86. |
A man stands in front of a hillock and fires a gun. He hears an echo after 1.5 sec. The distance of the hillock from the man is (velocity of sound in air is 330 m/s) [EAMCET (Eng.) 1998; CPMT 2000] |
| A. | 220 m |
| B. | 247.5 m |
| C. | \[{{n}_{1}}\tilde{\ }{{n}_{2}}\] |
| D. | 292.5 m |
| Answer» C. \[{{n}_{1}}\tilde{\ }{{n}_{2}}\] | |
| 87. |
The type of waves that can be propagated through solid is [CPMT 2000] |
| A. | Transverse |
| B. | Longitudinal |
| C. | 99 |
| D. | None of these |
| Answer» D. None of these | |
| 88. |
The minimum distance of reflector surface from the source for listening the echo of sound is [CPMT 1997; RPMT 1999; KCET 2000] |
| A. | 28 m |
| B. | 18 m |
| C. | 324 Hz |
| D. | 16.5 m |
| Answer» E. | |
| 89. |
A man standing on a cliff claps his hand hears its echo after 1 sec. If sound is reflected from another mountain and velocity of sound in air is 340 m/sec. Then the distance between the man and reflection point is [RPET 2000] |
| A. | 680 m |
| B. | 340 m |
| C. | 260 Hz |
| D. | 170 m |
| Answer» E. | |
| 90. |
Speed of sound at constant temperature depends on [RPET 2000; AIIMS 1998] |
| A. | Pressure |
| B. | Density of gas |
| C. | 192 Hz |
| D. | None of the above |
| Answer» E. | |
| 91. |
The speed of a wave in a certain medium is 960 m/s. If 3600 waves pass over a certain point of the medium in 1 minute, the wavelength is [MP PMT 2000] |
| A. | 2 metres |
| B. | 4 metres |
| C. | 4.86 ´1010 N/m3 |
| D. | 16 metres |
| Answer» E. | |
| 92. |
The temperature at which the speed of sound in air becomes double of its value at \[{{27}^{o}}C\] is [CPMT 1997; UPSEAT 2000; DPMT 2003] |
| A. | \[{{54}^{o}}C\] |
| B. | \[{{327}^{o}}C\] |
| C. | Ultrasonic wave |
| D. | \[-{{123}^{o}}C\] |
| Answer» D. \[-{{123}^{o}}C\] | |
| 93. |
The frequency of a sound wave is n and its velocity is v. If the frequency is increased to \[4n,\] the velocity of the wave will be [MP PET 2000] |
| A. | v |
| B. | \[2v\] |
| C. | Low temperature |
| D. | \[v/4\] |
| Answer» B. \[2v\] | |
| 94. |
When the temperature of an ideal gas is increased by 600 K, the velocity of sound in the gas becomes \[\sqrt{3}\] times the initial velocity in it. The initial temperature of the gas is [EAMCET (Med.) 2000] |
| A. | \[-{{73}^{o}}C\] |
| B. | \[{{27}^{o}}C\] |
| C. | 60 cm |
| D. | \[{{327}^{o}}C\] |
| Answer» C. 60 cm | |
| 95. |
Velocity of sound in air is [Pb. PMT 1999; UPSEAT 2000] |
| A. | Faster in dry air than in moist air |
| B. | Directly proportional to pressure |
| C. | 2p |
| D. | Independent of pressure of air |
| Answer» E. | |
| 96. |
A man sets his watch by the sound of a siren placed at a distance 1 km away. If the velocity of sound is 330 m/s [JIPMER 1999] |
| A. | His watch is set 3 sec. faster |
| B. | His watch is set 3 sec. slower |
| C. | Visible light wave |
| D. | None of the above |
| Answer» C. Visible light wave | |
| 97. |
When sound waves travel from air to water, which of the following remains constant [AFMC 1993; DCE 1999; CPMT 2004] |
| A. | Velocity |
| B. | Frequency |
| C. | Propagated waves |
| D. | All the above |
| Answer» C. Propagated waves | |
| 98. |
The echo of a gunshot is heard 8 sec. after the gun is fired. How far from him is the surface that reflects the sound (velocity of sound in air = 350 m/s) [JIPMER 1999] |
| A. | 1400 m |
| B. | 2800 m |
| C. | Both longitudinal and transverse elastic waves |
| D. | 350 m |
| Answer» B. 2800 m | |
| 99. |
A stone is dropped into a lake from a tower 500 metre high. The sound of the splash will be heard by the man approximately after [CPMT 1992; JIPMER 2001, 02; Kerala PMT 2005] |
| A. | 11.5 seconds |
| B. | 21 seconds |
| C. | Both longitudinal and transverse |
| D. | 14 seconds |
| Answer» B. 21 seconds | |
| 100. |
In a medium sound travels 2 km in 3 sec and in air, it travels 3 km in 10 sec. The ratio of the wavelengths of sound in the two media is [NTSE 1995] |
| A. | 1 : 8 |
| B. | 1 : 18 |
| C. | 5.5 mm, 20 KHz |
| D. | 20 : 9 |
| Answer» E. | |