MCQOPTIONS
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MCQOPTIONS
This section includes 189 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
A closed system is one in which heat and work crosses the boundary of the system but the mass of the working substance does not crosses the boundary of the system. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 52. |
Ericsson cycle consists of two constant pressure and two isothermal processes. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 53. |
The isothermal and isentropic processes are reversible non-flow processes. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 54. |
The blast furnace gas is a by-product in the production of pig iron in the blast furnace. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 55. |
Liquid fuels have lower efficiency than solid fuels. |
| A. | True |
| B. | False |
| Answer» C. | |
| 56. |
The heat absorbed during a polytropic process is |
| A. | x Workdone |
| B. | all of these |
| Answer» E. | |
| 57. |
Liquid fuels consist of hydrocarbons. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 58. |
The dual combustion cycle consists of one constant pressure, two constant volume and two isentropic processes. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 59. |
The standard value of atmospheric pressure taken at sea level is |
| A. | 1.013 bar |
| B. | 760 mm of Hg |
| C. | 1013 x 10 |
| D. | N/m |
| E. | all of these |
| Answer» E. all of these | |
| 60. |
The efficiency of Otto cycle depends upon the specific heats of the working substance. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 61. |
The absolute zero pressure can be attained at a temperature of |
| A. | 0°C |
| B. | 273°C |
| C. | 273 K |
| D. | none of these |
| Answer» E. | |
| 62. |
One kg of ethylene (CH) requires 2 kg of oxygen and produces 22/7 kg of carbon dioxide and __________ kg of water or steam. |
| A. | 9/7 |
| B. | 11/7 |
| C. | 7/4 |
| D. | 11/4 |
| Answer» B. 11/7 | |
| 63. |
The area under the temperature-entropy curve ( - curve) of any thermodynamic process represents |
| A. | heat absorbed |
| B. | heat rejected |
| C. | either (a) or (b) |
| D. | none of these |
| Answer» D. none of these | |
| 64. |
The free expansion process is a constant enthalpy process. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 65. |
The specific heat at constant volume is |
| A. | the amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure |
| B. | the amount of heat required to raise the temperature of unit mass of gas through one degree, at constant volume |
| C. | the amount of heat required to raise the temperature of 1 kg of water through one degree |
| D. | any one of the above |
| Answer» C. the amount of heat required to raise the temperature of 1 kg of water through one degree | |
| 66. |
The entropy of water at 0°C is assumed to be |
| A. | 1 |
| B. | 0 |
| C. | -1 |
| D. | 10 |
| Answer» C. -1 | |
| 67. |
The greater the pressure difference in throttling, the lesser is the irreversibility. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 68. |
During which of the following process does heat rejection takes place in Carnot cycle? |
| A. | Isothermal expansion |
| B. | Isentropic expansion |
| C. | Isothermal compression |
| D. | Isentropic compression |
| Answer» D. Isentropic compression | |
| 69. |
One m of methane (CH) requires 2m of oxygen and produces 1m of carbon dioxide and 2m of water or steam. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 70. |
Coke oven gas is obtained by burning coke in an oven. |
| A. | Agree |
| B. | Disagree |
| Answer» C. | |
| 71. |
A perpetual motion machine of the first kind is __________ according to first law of thermodynamics. |
| A. | possible |
| B. | impossible |
| Answer» C. | |
| 72. |
One kg of carbon requires 8/3 kg of oxygen for its complete combustion and produces 11/3 kg of carbon dioxide gas. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 73. |
A process, in which the gas is heated or expanded in such a way that product of its pressure and volume remains constant, is called isothermal process. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 74. |
The compression ratio for Diesel engines is |
| A. | 3 to 6 |
| B. | 5 to 8 |
| C. | 15 to 20 |
| D. | 20 to 30 |
| Answer» D. 20 to 30 | |
| 75. |
Which of the following is the correct statement of the second law of thermodynamics? |
| A. | It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work. |
| B. | It is impossible to transfer heat from a body at a lower temperature to a higher temperature, without the aid of an external source. |
| C. | There is a definite amount of mechanical energy, which can be obtained from a given quantity of heat energy. |
| D. | all of the above |
| Answer» E. | |
| 76. |
The heating and expanding of a gas is called thermodynamic system. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 77. |
The general gas equation is (where = Pressure, = Volume, = mass, = Absolute temperature, and = Gas constant) |
| A. | = |
| B. | = |
| C. | = |
| D. | = ( |
| E. | ) |
| Answer» B. = | |
| 78. |
The work ratio of simple gas turbine cycle depends upon |
| A. | maximum cycle temperature |
| B. | minimum cycle temperature |
| C. | pressure ratio |
| D. | all of these |
| Answer» E. | |
| 79. |
The gas constant () is equal to the |
| A. | sum of two specific heats |
| B. | difference of two specific heats |
| C. | product of two specific heats |
| D. | ratio of two specific heats |
| Answer» C. product of two specific heats | |
| 80. |
One kg of hydrogen requires 8 kg of oxygen and produces |
| A. | 1 kg of water |
| B. | 7 kg of water |
| C. | 8 kg of water |
| D. | 9 kg of water |
| Answer» E. | |
| 81. |
Boyle's law states that change of internal energy of a perfect gas is directly proportional to the change of temperature. |
| A. | Agree |
| B. | Disagree |
| Answer» C. | |
| 82. |
The unit of power in S.I. units is kilowatt. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 83. |
The increase in entropy of a system represents |
| A. | increase in availability of energy |
| B. | increase in temperature |
| C. | decrease in pressure |
| D. | degradation of energy |
| Answer» E. | |
| 84. |
The reading of the pressure gauge fitted on a vessel is 25 bar. The atmospheric pressure is 1.03 bar and the value of '' is 9.81 m/s. The absolute pressure in the vessel is |
| A. | 23.97 bar |
| B. | 25 bar |
| C. | 26.03 bar |
| D. | 34.81 bar |
| Answer» D. 34.81 bar | |
| 85. |
The ratio of specific heat at constant pressure () and specific heat at constant volume () is always __________ one. |
| A. | equal to |
| B. | less than |
| C. | greater than |
| Answer» D. | |
| 86. |
The isothermal and adiabatic processes are regarded as |
| A. | reversible process |
| B. | irreversible process |
| C. | reversible or irreversible process |
| D. | none of these |
| Answer» B. irreversible process | |
| 87. |
The variables which control the physical properties of a perfect gas are |
| A. | pressure exerted by the gas |
| B. | volume occupied by the gas |
| C. | temperature of the gas |
| D. | all of these |
| Answer» E. | |
| 88. |
The heat flows from a cold body to a hot body with the aid of an external source. This statement is given by |
| A. | Kelvin |
| B. | Joule |
| C. | Clausis |
| D. | Gay-Lussac |
| Answer» D. Gay-Lussac | |
| 89. |
The lower calorific value of fuel may be obtained by adding the heat of steam formed during combustion to the higher calorific value. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 90. |
One kg of carbon monoxide requires 4/7 kg of oxygen and produces |
| A. | 11/3 kg of carbon dioxide gas |
| B. | 7/3 kg of carbon monoxide gas |
| C. | 11/7 kg of carbon dioxide gas |
| D. | 8/3 kg of carbon monoxide gas |
| Answer» D. 8/3 kg of carbon monoxide gas | |
| 91. |
The molecular mass expresssed in gram (i.e. 1 g - mole) of all gases, at N. T. P., occupies a volume of |
| A. | 0.224 litres |
| B. | 2.24 litres |
| C. | 22.4 litres |
| D. | 224 litres |
| Answer» D. 224 litres | |
| 92. |
The heating of gas at constant volume is governed by |
| A. | Boyle's law |
| B. | Charles' law |
| C. | Gay-Lussac law |
| D. | Avogadro's law |
| Answer» D. Avogadro's law | |
| 93. |
The absolute pressure of a given mass of a perfect gas varies inversely as its volume, when the temperature remains constant. This statement is known as Boyle's law. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 94. |
The fuel mostly used in cement industry and in metallurgical processes is |
| A. | wood charcoal |
| B. | bituminous coke |
| C. | pulverised coal |
| D. | coke |
| Answer» D. coke | |
| 95. |
Liquid fuels have higher calorific value than solid fuels. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 96. |
The free expansion process is __________ non-flow process. |
| A. | reversible |
| B. | irreversible |
| Answer» C. | |
| 97. |
A mixture of gas expands from 0.03 m to 0.06 m at a constant pressure of 1 MPa and absorbs 84 kJ of heat during the process. The change in internal energy of the mixture is |
| A. | 30 kJ |
| B. | 54 kJ |
| C. | 84 kJ |
| D. | 114 kJ |
| Answer» C. 84 kJ | |
| 98. |
The gas constant () is equal to the __________ of two specific heats. |
| A. | sum |
| B. | difference |
| C. | product |
| D. | ratio |
| Answer» C. product | |
| 99. |
One reversible heat engine operates between 1600 K and K and another reversible heat engine operates between K and 400 K. If both the engines have the same heat input and output, then temperature is equal to |
| A. | 800K |
| B. | 1000K |
| C. | 1200K |
| D. | 1400K |
| Answer» B. 1000K | |
| 100. |
When the gas is heated at constant volume, the heat supplied |
| A. | increases the internal energy of the gas and increases the temperature of the gas |
| B. | does some external work during expansion |
| C. | Both (A) and (B) |
| D. | None of these |
| Answer» B. does some external work during expansion | |