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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.
| 551. |
The general gas energy equation is (where Q1 - 2 = Heat supplied, dU = Change in internal energy, and W1 - 2 = Work done in heat units) |
| A. | Q1 - 2 = dU + W1 - 2 |
| B. | Q1 - 2 = dU - W1 - 2 |
| C. | Q1 - 2 = dU/W1 - 2 |
| D. | Q1 - 2 = dU × W1 - 2 |
| Answer» B. Q1 - 2 = dU - W1 - 2 | |
| 552. |
The value of n = 1 in the polytropic process indicates it to be |
| A. | Reversible process |
| B. | Isothermal process |
| C. | Adiabatic process |
| D. | Irreversible process |
| Answer» C. Adiabatic process | |
| 553. |
Which law states that the internal energy of a gas is a function of temperature? |
| A. | Charles' law |
| B. | Joule's law |
| C. | Boyle's law |
| D. | There is no such law |
| Answer» C. Boyle's law | |
| 554. |
The standard value of atmospheric pressure taken at sea level is |
| A. | 1.013 bar |
| B. | 760 mm of Hg |
| C. | 1013 × 102 N/m2 |
| D. | All of these |
| Answer» E. | |
| 555. |
In order that a cycle be reversible, following must be satisfied |
| A. | Free expansion or friction resisted expansion/compression process should not be encountered |
| B. | When heat is being absorbed, temperature of hot source and working substance should be same |
| C. | When beat is being rejected, temperature of cold source and working substance should be same |
| D. | All of the above |
| Answer» E. | |
| 556. |
The energy of molecular motion appears as |
| A. | Heat |
| B. | Potential energy |
| C. | Surface tension |
| D. | Friction |
| Answer» B. Potential energy | |
| 557. |
According to Avogadro's law, for a given pressure and temperature, each molecule of a gas |
| A. | Occupies same volume |
| B. | Occupies volume proportional to its specific weight |
| C. | Occupies volume inversely proportional to its molecular weight |
| D. | Occupies volume inversely proportional to its specific weight |
| Answer» B. Occupies volume proportional to its specific weight | |
| 558. |
Which of the following is an intensive property of a thermodynamic system? |
| A. | Mass |
| B. | Temperature |
| C. | Energy |
| D. | Volume |
| Answer» C. Energy | |
| 559. |
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 | |
| 560. |
For the same compression ratio, the efficiency of dual combustion cycle is |
| A. | Greater than Diesel cycle and less than Otto cycle |
| B. | Greater than Diesel cycle |
| C. | Less than Diesel cycle |
| D. | Less than Diesel cycle and greater than Otto cycle |
| Answer» B. Greater than Diesel cycle | |
| 561. |
The atomic mass of oxygen is |
| A. | 14 |
| B. | 16 |
| C. | 18 |
| D. | 121 |
| Answer» C. 18 | |
| 562. |
An isolated system is one in which |
| A. | Mass does not cross boundaries of the system, though energy may do so |
| B. | Neither mass nor energy crosses the boundaries of the system |
| C. | Both energy and mass cross the boundaries of the system |
| D. | Mass crosses the boundary but not the energy |
| Answer» C. Both energy and mass cross the boundaries of the system | |
| 563. |
A closed system is one in which |
| A. | Mass does not cross boundaries of the system, though energy may do so |
| B. | Mass crosses the boundary but not the energy |
| C. | Neither mass nor energy crosses the boundaries of the system |
| D. | Both energy and mass cross the boundaries of the system |
| Answer» B. Mass crosses the boundary but not the energy | |
| 564. |
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 | |
| 565. |
The state of a substance whose evaporation from its liquid state is complete, is known as |
| A. | Perfect gas |
| B. | Vapour |
| C. | Steam |
| D. | Air |
| Answer» B. Vapour | |
| 566. |
Boyle's law i.e. pV = constant is applicable to gases under |
| A. | All ranges of pressures |
| B. | Only small range of pressures |
| C. | High range of pressures |
| D. | Steady change of pressures |
| Answer» C. High range of pressures | |
| 567. |
The efficiency of Carnot cycle is maximum for |
| A. | Gas engine |
| B. | Petrol engine |
| C. | Steam engine |
| D. | Reversible engine |
| Answer» E. | |
| 568. |
Petrol is distilled at |
| A. | 65° to 220°C |
| B. | 220° to 345°C |
| C. | 345° to 470°C |
| D. | 470° to 550°C |
| Answer» B. 220° to 345°C | |
| 569. |
General gas equation is |
| A. | PV=nRT |
| B. | PV=mRT |
| C. | PV = C |
| D. | PV=KiRT |
| Answer» C. PV = C | |
| 570. |
In S. I. units, the value of the universal gas constant is |
| A. | 8.314 J/kg mole-K |
| B. | 83.14 J/kg mole-K |
| C. | 831.4 J/kg mole-K |
| D. | 8314 J/kg mole-K |
| Answer» E. | |
| 571. |
If value of n is infinitely large in a polytropic process pVn = C, then the process is known as constant |
| A. | Volume |
| B. | Pressure |
| C. | Temperature |
| D. | Enthalpy |
| Answer» B. Pressure | |
| 572. |
Change in enthalpy of a system is the heat supplied at |
| A. | Constant pressure |
| B. | Constant temperature |
| C. | Constant volume |
| D. | Constant entropy |
| Answer» B. Constant temperature | |
| 573. |
The specific heat of water is |
| A. | 2.512 |
| B. | 1.817 |
| C. | 4.187 |
| D. | None of these |
| Answer» D. None of these | |
| 574. |
The amount of heat generated per kg of fuel is known as |
| A. | Calorific value |
| B. | Heat energy |
| C. | Lower calorific value |
| D. | Higher calorific value |
| Answer» B. Heat energy | |
| 575. |
For which of the following substances, the gas laws can be used with minimum error |
| A. | Dry steam |
| B. | Wet steam |
| C. | Saturated steam |
| D. | Superheated steam |
| Answer» E. | |
| 576. |
The pressure exerted by an ideal gas is ________ of the kinetic energy of all the molecules contained in a unit volume of gas. |
| A. | One-third |
| B. | Three-forth |
| C. | One-half |
| D. | Two-third |
| Answer» E. | |
| 577. |
The universal gas constant (or molar constant) of a gas is the product of |
| A. | Molecular mass of the gas and the gas constant |
| B. | Atomic mass of the gas and the gas constant |
| C. | Molecular mass of the gas and the specific heat at constant pressure |
| D. | Molecular mass of the gas and the specific heat at constant volume |
| Answer» B. Atomic mass of the gas and the gas constant | |
| 578. |
The unit of energy is S. I. units is |
| A. | Joule (J) |
| B. | Joule meter (Jm) |
| C. | Watt (W) |
| D. | Joule/meter (J/m) |
| Answer» B. Joule meter (Jm) | |
| 579. |
The hard coke is obtained when carbonization of coal is carried out at |
| A. | 500° to 700°C |
| B. | 700° to 900°C |
| C. | 300° to 500°C |
| D. | 900° to 1100°C |
| Answer» E. | |
| 580. |
The value of the product of molecular weight and the gas characteristic constant for all the gases in M.K.S. unit is |
| A. | 29.27 kgfm/mol °K |
| B. | 8314 kgfm/mol °K |
| C. | 848 kgfm/mol °K |
| D. | 427 kgfm/mol °K |
| Answer» D. 427 kgfm/mol °K | |
| 581. |
Which of the following has the minimum atomic mass? |
| A. | Sulphur |
| B. | Nitrogen |
| C. | Oxygen |
| D. | Carbon |
| Answer» E. | |
| 582. |
The behavior of super-heated vapour is similar to that of |
| A. | Perfect gas |
| B. | Air |
| C. | Steam |
| D. | Ordinary gas |
| Answer» B. Air | |
| 583. |
Stirling and Ericsson cycles are |
| A. | Quasi-static cycles |
| B. | Reversible cycles |
| C. | Semi-reversible cycles |
| D. | Irreversible cycles |
| Answer» C. Semi-reversible cycles | |
| 584. |
The fuel mostly used in cement industry and in metallurgical processes is |
| A. | Wood charcoal |
| B. | Bituminous coke |
| C. | Pulverized coal |
| D. | Coke |
| Answer» D. Coke | |
| 585. |
The index of compression ‘n’ tends to reach ratio of specific heats ‘y’ when |
| A. | Flow is uniform and steady |
| B. | Process is isentropic |
| C. | Process is isothermal |
| D. | Process is isentropic and specific heat does not change with temperature |
| Answer» E. | |
| 586. |
Universal gas constant is defined as equal to product of the molecular weight of the gas and |
| A. | Specific heat at constant pressure |
| B. | Specific heat at constant volume |
| C. | Ratio of two specific heats |
| D. | Gas constant |
| Answer» E. | |
| 587. |
Heat and work are |
| A. | Point functions |
| B. | System properties |
| C. | Path functions |
| D. | Intensive properties |
| Answer» D. Intensive properties | |
| 588. |
The oxygen atom is ________ times heavier than the hydrogen atom. |
| A. | 2 |
| B. | 8 |
| C. | 16 |
| D. | 32 |
| Answer» D. 32 | |
| 589. |
One molecule of oxygen is __________ times heavier than the hydrogen atom. |
| A. | 12 |
| B. | 14 |
| C. | 16 |
| D. | 32 |
| Answer» E. | |
| 590. |
When a gas is heated, change takes place in |
| A. | Temperature |
| B. | Pressure |
| C. | Volume |
| D. | All of these |
| Answer» E. | |
| 591. |
According to Dalton's law, the total pressure of the mixture of gases is equal to |
| A. | Greater of the partial pressures of all |
| B. | Average of the partial pressures of all |
| C. | Sum of the partial pressures of all |
| D. | Sum of the partial pressures of all divided by average molecular weight |
| Answer» D. Sum of the partial pressures of all divided by average molecular weight | |
| 592. |
Gases have |
| A. | Only one value of specific heat |
| B. | Two values of specific heat |
| C. | No value of specific heat |
| D. | Under some conditions one value and sometimes two values of specific heat |
| Answer» C. No value of specific heat | |
| 593. |
On weight basis, air contains following parts of oxygen |
| A. | 21 |
| B. | 23 |
| C. | 25 |
| D. | 73 |
| Answer» C. 25 | |
| 594. |
The fuel mostly used in blast furnace for extracting pig iron from iron ores is |
| A. | Hard coke |
| B. | Soft coke |
| C. | Pulverized coal |
| D. | Bituminous coal |
| Answer» B. Soft coke | |
| 595. |
Work done is zero for the following process |
| A. | Constant volume |
| B. | Free expansion |
| C. | Throttling |
| D. | All of the above |
| Answer» E. | |
| 596. |
1 kgf/cm² is equal to |
| A. | 760 mm Hg |
| B. | Zero mm Hg |
| C. | 735.6 mm Hg |
| D. | 1 mm Hg |
| Answer» D. 1 mm Hg | |
| 597. |
Which of the following is the correct statement of the second law of thermodynamics? |
| A. | There is a definite amount of mechanical energy, which can be obtained from a given quantity of heat energy |
| 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. | It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work |
| D. | All of the above |
| Answer» E. | |
| 598. |
Which of the following statement is correct according to Clausis statement of second law of thermodynamics? |
| A. | It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature. |
| B. | It is impossible to transfer heat from a body at a lower temperature to a body at a higher temperature, without the aid of an external source. |
| C. | It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature by using refrigeration cycle. |
| D. | None of the above |
| Answer» C. It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature by using refrigeration cycle. | |
| 599. |
The heat and work are mutually convertible. This statement is called __________ law of thermodynamics. |
| A. | Zeroth |
| B. | First |
| C. | Second |
| D. | Third |
| Answer» C. Second | |
| 600. |
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 | |