MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 205 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
If the absolute temperature of a perfectly black body is doubled, then its rate of radiation increases by a factor of |
| A. | 2 |
| B. | 4 |
| C. | 8 |
| D. | 16 |
| Answer» E. | |
| 52. |
The absorptive power of a perfectly black body is |
| A. | 1 |
| B. | 0 |
| C. | 2 |
| D. | None |
| Answer» B. 0 | |
| 53. |
Relation between the colour and the temperature of a star is given by |
| A. | Wean's displacement law |
| B. | Planck's law |
| C. | Hubble's law |
| D. | Hippacrus rule |
| Answer» B. Planck's law | |
| 54. |
A hot body will radiate maximum energy if its surface is |
| A. | White and rough |
| B. | White and polished |
| C. | Black and rough |
| D. | Black and polished |
| Answer» D. Black and polished | |
| 55. |
The relative humidity of air can decrease in spite of an increase in the absolute humidity when the |
| A. | Pressure rises |
| B. | Pressure falls |
| C. | Temperature rises |
| D. | Temperature falls |
| Answer» D. Temperature falls | |
| 56. |
Which of the following is the best conductor of the heat? |
| A. | Mercury |
| B. | Silver |
| C. | Leather |
| D. | Benzene |
| Answer» C. Leather | |
| 57. |
In an isothermal change an ideal gas obey's |
| A. | Boyle's law |
| B. | Charle's law |
| C. | Gay-Lussac's law |
| D. | None of the above |
| Answer» B. Charle's law | |
| 58. |
A refrigerator, with its powers on, is kept in closed room with its door open. The temperature of the room will |
| A. | Rise |
| B. | Fall |
| C. | Remains the same |
| D. | None of these |
| Answer» B. Fall | |
| 59. |
A gas has |
| A. | One specific heat |
| B. | Two specific heat |
| C. | Three specific heat |
| D. | linfinite specific heat |
| Answer» E. | |
| 60. |
The thermal conductivity of a plate depends on |
| A. | The temperature difference between the two sides |
| B. | The thickness of the plate |
| C. | The area of the plate |
| D. | None of the above |
| Answer» D. None of the above | |
| 61. |
The boiling point of a liquid is |
| A. | Affected by addition of soluble solid |
| B. | Increases with increase of pressure |
| C. | Both (a) and (b) |
| D. | None of the above |
| Answer» D. None of the above | |
| 62. |
If the temperature inside a room is increased, the relative humidity will |
| A. | Increase |
| B. | Decrease |
| C. | Remain unchanged |
| D. | None of these |
| Answer» C. Remain unchanged | |
| 63. |
A sealed container contains helium gas at 300 K. If it is hated to 600 K the average kinetic energy of the helium atoms |
| A. | Remain unchanged |
| B. | Is doubled |
| C. | Becomes 2 times |
| D. | None of these |
| Answer» C. Becomes 2 times | |
| 64. |
A gas is enclosed in a container which is then placed on fast moving train. The temperature of the gas |
| A. | Rises |
| B. | Falls |
| C. | Remain unchanged |
| D. | Becomes unsteady |
| Answer» D. Becomes unsteady | |
| 65. |
For an ideal gas the interparticle interaction is |
| A. | Attractive |
| B. | Repulsive |
| C. | Very large |
| D. | Zero |
| Answer» E. | |
| 66. |
The first law of thermodynamics is concerned with the conservation of |
| A. | Number of molecules |
| B. | Energy |
| C. | Numbers of moles |
| D. | Temperature |
| Answer» C. Numbers of moles | |
| 67. |
Heat given to an ideal gas under isothermal conditions is used |
| A. | Increasing the temperature |
| B. | In doing external work |
| C. | In increasing the internal energy |
| D. | None of the above |
| Answer» C. In increasing the internal energy | |
| 68. |
In a cyclic process the change in the in energy of system is |
| A. | Maximum but not zero |
| B. | Maximum but not infinite |
| C. | Zero |
| D. | Infinite |
| Answer» D. Infinite | |
| 69. |
The temperature at which the vapour pressure of a liquid becomes equal to the external (atmospheric) pressure is its |
| A. | Melting point |
| B. | Boiling point |
| C. | Inversion point |
| D. | None of these |
| Answer» C. Inversion point | |
| 70. |
300 g of water at 25 C is added to 100 g of ice at 0 C. The final temperature of the mixture is |
| A. | 0 C |
| B. | 1 C |
| C. | 2 C |
| D. | 3 C |
| Answer» B. 1 C | |
| 71. |
The process in which no heat enters or leaves the system is termed as |
| A. | Isochoric |
| B. | Isobaric |
| C. | Isothermal |
| D. | Adiabatic |
| Answer» E. | |
| 72. |
Which is the fastest mode of heat loss? |
| A. | Conduction |
| B. | Convection |
| C. | Radiation |
| D. | All are equally fast |
| Answer» C. Radiation | |
| 73. |
A solid metal ball has a spherical cavity. If the ball is heated, the volume of the cavity will |
| A. | Increase |
| B. | Decrease |
| C. | Remain unaffected |
| D. | None of these |
| Answer» B. Decrease | |
| 74. |
A metal sheet with circular hole is heated. The hole will |
| A. | Contract |
| B. | Expand |
| C. | Remain unaffected |
| D. | None of these |
| Answer» C. Remain unaffected | |
| 75. |
Mode of transmission of heat in which heat carried by a moving particles is |
| A. | conduction |
| B. | Radiation |
| C. | Wave motion |
| D. | Convection |
| Answer» E. | |
| 76. |
At dew point RH is |
| A. | 100% |
| B. | 50% |
| C. | 25% |
| D. | 0% |
| Answer» B. 50% | |
| 77. |
Thermo flask prevents heat loss by |
| A. | Radiation |
| B. | Conduction |
| C. | Convection |
| D. | All of these |
| Answer» E. | |
| 78. |
When water is heated from 0 to 10 C its volume |
| A. | Increases |
| B. | Decreases |
| C. | Dose not change |
| D. | First decreases and then increases |
| Answer» E. | |
| 79. |
The change of a solid into vapour directly is called |
| A. | Vaporization |
| B. | Freezing |
| C. | Melting |
| D. | Sublimation |
| Answer» E. | |
| 80. |
If the temperature of a hot body is increased by 50% the amount of radiation emitted by it increases approximately by |
| A. | 225% |
| B. | 250% |
| C. | 400% |
| D. | 500% |
| Answer» D. 500% | |
| 81. |
The change in temperature of a body is 50 C. The change on kelvin scale is |
| A. | 50 K |
| B. | 60 K |
| C. | 70 K |
| D. | 323 K |
| Answer» B. 60 K | |
| 82. |
A graph is plotted taking C along the Y-axis and of K along the X-axis. It is a / an |
| A. | Parabola |
| B. | Straight line |
| C. | Ellipse |
| D. | Circle |
| Answer» C. Ellipse | |
| 83. |
Calorimeters are generally made of |
| A. | Copper |
| B. | Brass |
| C. | Aluminium |
| D. | Zinc |
| Answer» B. Brass | |
| 84. |
If RH is high |
| A. | We feel sultry |
| B. | We perspireless |
| C. | Clothes do not dry easily |
| D. | All of these are correct |
| Answer» E. | |
| 85. |
Water evaporates at atmospheric pressure at a certain rate. If now the some water is placed in vacuum, the rate of evaporation |
| A. | Will increase |
| B. | Will decrease |
| C. | Will remain unchanged |
| D. | None of these |
| Answer» B. Will decrease | |
| 86. |
The quantity of heat required to change the temperature of 1 kg. of substance by 1 C is called its |
| A. | Specific heat |
| B. | The total energy |
| C. | The latent-heat |
| D. | heat of fusion |
| Answer» B. The total energy | |
| 87. |
When temperature is gradually decreased the specific heat of substance is |
| A. | Decreased |
| B. | Increased |
| C. | Remain unchanged |
| D. | None of these |
| Answer» B. Increased | |
| 88. |
In which mode of transmission, the heat waves travel along straight line with the speed of light? |
| A. | Natural convection |
| B. | Thermal radiation |
| C. | Forced convenction |
| D. | Thermal conduction |
| Answer» C. Forced convenction | |
| 89. |
When an object is heated, the molecules of that object |
| A. | Began to move faster |
| B. | Lose energy |
| C. | Become heavier |
| D. | Become lighter |
| Answer» B. Lose energy | |
| 90. |
The range of platinum resistance thermometer is |
| A. | From - 200 C to 1600 C |
| B. | From - 200 C to 1200 C |
| C. | From - 200 C to 800 C |
| D. | From - 0 C to 1200 C |
| Answer» C. From - 200 C to 800 C | |
| 91. |
For the measurement of temperature of the order of 400 C, we will prefer |
| A. | Mercury thermometer |
| B. | Alcohol thermometer |
| C. | Radiation thermometer |
| D. | Thermocouple |
| Answer» E. | |
| 92. |
When lake starts freezing the formation of the ice will start first at the |
| A. | Bottom |
| B. | Middle |
| C. | Top |
| D. | None of these |
| Answer» D. None of these | |
| 93. |
Fahrenheit scale divides two fixed points into |
| A. | 180 parts |
| B. | 212 parts |
| C. | 100 parts |
| D. | 32 parts |
| Answer» B. 212 parts | |
| 94. |
The absolute zero on celsius scale is |
| A. | -200 C |
| B. | -273.15 C |
| C. | -373.15 C |
| D. | none of these |
| Answer» C. -373.15 C | |
| 95. |
SI unit of heat is |
| A. | Calorie |
| B. | Joule |
| C. | Kilo calorie |
| D. | Kelvin |
| Answer» C. Kilo calorie | |
| 96. |
Two block of lead, one twice as heavy as the other, are at 50 C. The ratio of heat content of the heavier block to that of the lighter block is |
| A. | 0.5 |
| B. | 1 |
| C. | 2 |
| D. | 4 |
| Answer» D. 4 | |
| 97. |
On thermometer, the freezing point of water is marked as 20 and the boiling of water is marked as 150 A temperature of 60 C will be read on this thermometer as |
| A. | 110 |
| B. | 98 |
| C. | 75 |
| D. | 40 |
| Answer» C. 75 | |
| 98. |
One calorie is the heat required to raise the temperature of 1g of water by |
| A. | 1 C |
| B. | 1K |
| C. | 1 F |
| D. | None of these |
| Answer» B. 1K | |
| 99. |
A bimetal made copper and iron strips welded together is straight at room temperature. It is held vertically with iron strip towards left and copper towards right. If this bimetal is heated, it will |
| A. | Remain straight |
| B. | Bend towards right |
| C. | Bend towards left |
| D. | Bend towards bottom |
| Answer» D. Bend towards bottom | |
| 100. |
Freezing mixture is a mixture |
| A. | Which solidifies water |
| B. | Freezes at 0°:C |
| C. | Which produce's very low temperature |
| D. | Which is used in medicine |
| Answer» D. Which is used in medicine | |