MCQOPTIONS
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MCQOPTIONS
This section includes 1092 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1051. |
The ratio of molar specific heats for mono-atomic gas is |
| A. | 1 |
| B. | 1.4 |
| C. | 1.67 |
| D. | 1.87 |
| Answer» D. 1.87 | |
| 1052. |
First law of thermodynamics |
| A. | Enables to determine change in internal energy of the system |
| B. | Does not enable to determine change in entropy |
| C. | Provides relationship between heat, work and internal energy |
| D. | All of the above |
| Answer» E. | |
| 1053. |
The mass of excess air supplied is equal to |
| A. | (23/100) √ó Mass of excess carbon |
| B. | (23/100) √ó Mass of excess oxygen |
| C. | (100/23) √ó Mass of excess carbon |
| D. | (100/23) √ó Mass of excess oxygen |
| Answer» E. | |
| 1054. |
The compression ratio for petrol engines is |
| A. | 3 to 6 |
| B. | 5 to 8 |
| C. | 10 to 20 |
| D. | 15 to 30 |
| Answer» C. 10 to 20 | |
| 1055. |
In an isothermal process, |
| A. | There is no change in temperature |
| B. | There is no change in enthalpy |
| C. | There is no change in internal energy |
| D. | All of these |
| Answer» E. | |
| 1056. |
If a gas vapour is allowed to expand through a very minute aperture, then such a process is known as |
| A. | Free expansion |
| B. | Hyperbolic expansion |
| C. | Adiabatic expansion |
| D. | Throttling |
| Answer» E. | |
| 1057. |
The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is |
| A. | Equal to one |
| B. | Less than one |
| C. | Greater than one |
| D. | None of these |
| Answer» D. None of these | |
| 1058. |
The value of one bar (in S. I. units) is equal to |
| A. | 1 √ó 102 N/m2 |
| B. | 1 √ó 103 N/m2 |
| C. | 1 √ó 104 N/m2 |
| D. | 1 √ó 105 N/m2 |
| Answer» E. | |
| 1059. |
Diesel cycle consists of following four processes |
| A. | Two isothermal and two isentropic |
| B. | Two isentropic and two constant volumes |
| C. | Two isentropic, one constant volume and one constant pressure |
| D. | Two isentropic and two constant pressures |
| Answer» D. Two isentropic and two constant pressures | |
| 1060. |
Which of the following process can be made reversible with the help of a regenerator? |
| A. | Constant pressure process |
| B. | Constant volume process |
| C. | Constant pvn process |
| D. | All of these |
| Answer» E. | |
| 1061. |
One kg of carbon monoxide requires _________kg of oxygen to produce 11/7 kg of carbon dioxide gas. |
| A. | 11/7 |
| B. | 9/7 |
| C. | 4/7 |
| D. | All of the above |
| Answer» D. All of the above | |
| 1062. |
Temperature of a gas is produced due to |
| A. | Its heating value |
| B. | Kinetic energy of molecules |
| C. | Repulsion of molecules |
| D. | Surface tension of molecules |
| Answer» C. Repulsion of molecules | |
| 1063. |
Kelvin Planck's law deals with |
| A. | Conservation of heat |
| B. | Conservation of work |
| C. | Conversion of heat into work |
| D. | Conversion of work into heat |
| Answer» D. Conversion of work into heat | |
| 1064. |
The area under the temperature-entropy curve (T - s 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 | |
| 1065. |
Which of the following cycles is not a reversible cycle? |
| A. | Carnot |
| B. | Ericsson |
| C. | Stirling |
| D. | None of the above |
| Answer» E. | |
| 1066. |
When a system changes its state from one equilibrium state to another equilibrium state, then the path of successive states through which the system has passed, is known as |
| A. | Thermodynamic law |
| B. | Thermodynamic process |
| C. | Thermodynamic cycle |
| D. | None of these |
| Answer» C. Thermodynamic cycle | |
| 1067. |
The kinetic energy per kg molecule of any gas at absolute temperature T is equal to (where Ru = Universal gas constant) |
| A. | Ru √ó T |
| B. | 1.5 Ru √ó T |
| C. | 2 Ru √ó T |
| D. | 3 Ru √ó T |
| Answer» C. 2 Ru ‚àö√≥ T | |
| 1068. |
Addition of heat at constant pressure to a gas results in |
| A. | Raising its temperature |
| B. | Raising its pressure |
| C. | Raising its volume |
| D. | Raising its temperature and doing external work |
| Answer» E. | |
| 1069. |
First law of thermodynamics furnishes the relationship between |
| A. | Heat and work |
| B. | Heat, work and properties of the system |
| C. | Various properties of the system |
| D. | Various thermodynamic processes |
| Answer» C. Various properties of the system | |
| 1070. |
When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is called |
| A. | Zeroth law of thermodynamics |
| B. | First law of thermodynamics |
| C. | Second law of thermodynamics |
| D. | Kelvin Planck's law |
| Answer» B. First law of thermodynamics | |
| 1071. |
The heat and mechanical energies are mutually convertible. This statement was established by |
| A. | Boyle |
| B. | Charles |
| C. | Joule |
| D. | None of these |
| Answer» D. None of these | |
| 1072. |
Thermal power plant works on |
| A. | Carnot cycle |
| B. | Joule cycle |
| C. | Rankine cycle |
| D. | Otto cycle |
| Answer» D. Otto cycle | |
| 1073. |
Carnot cycle efficiency depends upon |
| A. | Properties of the medium/substance used |
| B. | Condition of engine |
| C. | Working condition |
| D. | Temperature range of operation |
| Answer» E. | |
| 1074. |
Superheated vapour behaves |
| A. | Exactly as gas |
| B. | As steam |
| C. | As ordinary vapour |
| D. | Approximately as a gas |
| Answer» E. | |
| 1075. |
For the constant pressure and heat input, the air standard efficiency of gas power cycle is in the order |
| A. | Dual cycle, Diesel cycle, Otto cycle |
| B. | Otto cycle, Diesel cycle, Dual cycle |
| C. | Dual cycle, Otto cycle, Diesel cycle |
| D. | Diesel cycle, Otto cycle, Dual cycle |
| Answer» B. Otto cycle, Diesel cycle, Dual cycle | |
| 1076. |
The heat energy stored in the gas and used for raising the temperature of the gas is known as |
| A. | External energy |
| B. | Internal energy |
| C. | Kinetic energy |
| D. | Molecular energy |
| Answer» C. Kinetic energy | |
| 1077. |
One Joule (J) is equal to |
| A. | 1 kN-m |
| B. | 1 N-m |
| C. | 10 kN-m/s |
| D. | 10 N-m/s |
| Answer» C. 10 kN-m/s | |
| 1078. |
Reversed Joule cycle is known as |
| A. | Carnot cycle |
| B. | Bell-Coleman cycle |
| C. | Rankine cycle |
| D. | Stirling cycle |
| Answer» C. Rankine cycle | |
| 1079. |
The efficiency of Diesel cycle with decrease in cut-off |
| A. | Increases |
| B. | Decreases |
| C. | First increases and then decreases |
| D. | First decreases and then increases |
| Answer» B. Decreases | |
| 1080. |
Properties of substances like pressure, temperature and density, in thermodynamic coordinates are |
| A. | Path functions |
| B. | Point functions |
| C. | Cyclic functions |
| D. | Real functions |
| Answer» C. Cyclic functions | |
| 1081. |
According to Regnault's law, the specific heat at constant pressure (cp) and specific heat at constant volume (cv) _________ with the change in pressure and temperature of the gas. |
| A. | Change |
| B. | Do not change |
| C. | Both (A) and (B) |
| D. | None of these |
| Answer» C. Both (A) and (B) | |
| 1082. |
The first law of thermodynamics is the law of |
| A. | Conservation of mass |
| B. | Conservation of energy |
| C. | Conservation of momentum |
| D. | Conservation of heat |
| Answer» C. Conservation of momentum | |
| 1083. |
On volume basis, air contains following parts of oxygen |
| A. | 21 |
| B. | 23 |
| C. | 25 |
| D. | 77 |
| Answer» B. 23 | |
| 1084. |
One kg of ethylene (C2H4) 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 | |
| 1085. |
A sudden fall in the barometer reading is a sign of approaching |
| A. | Fine weather |
| B. | Rains |
| C. | Storm |
| D. | Cold wave |
| Answer» D. Cold wave | |
| 1086. |
The ideal efficiency of a Brayton cycle with regeneration, with increase in pressure ratio will |
| A. | Increase |
| B. | Decrease |
| C. | Remain unchanged |
| D. | Increase/decrease depending on application |
| Answer» C. Remain unchanged | |
| 1087. |
The volumetric or molar specific heat at constant pressure is the product of |
| A. | Molecular mass of the gas and the specific heat at constant volume |
| B. | Atomic mass of the gas and the gas constant |
| C. | Molecular mass of the gas and the gas constant |
| D. | None of the above |
| Answer» E. | |
| 1088. |
The value of gas constant (R) in S. I. units is |
| A. | 0.287 J/kgK |
| B. | 2.87 J/kgK |
| C. | 28.7 J/kgK |
| D. | 287 J/kgK |
| Answer» E. | |
| 1089. |
For a perfect gas, according to Boyle’s law (where P = Absolute pressure, V = Volume and T = Absolute temperature)# |
| A. | V/T = constant, if p is kept constant |
| B. | P v = constant, if T is kept constant |
| C. | T/P = constant, if v is kept constant |
| D. | P/T = constant, if v is kept constant |
| Answer» C. T/P = constant, if v is kept constant | |
| 1090. |
The calorific value of gaseous fuel is expressed in |
| A. | kJ |
| B. | kJ/kg |
| C. | kJ/m2 |
| D. | kJ/m3 |
| Answer» E. | |
| 1091. |
According to Kelvin-Planck’s statement of second law of thermodynamics,# |
| A. | It is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work |
| B. | It is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body |
| C. | It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work |
| D. | None of the above |
| Answer» D. None of the above | |
| 1092. |
One kg of carbon produces __________ kg of carbon dioxide. |
| A. | 3/7 |
| B. | 7/3 |
| C. | 11/3 |
| D. | 3/11 |
| Answer» D. 3/11 | |