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MCQOPTIONS
This section includes 4791 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 2501. |
One Joule (J) is equal to |
| A. | 1 N-m |
| B. | 1 kN-m |
| C. | 10 N-m/s |
| D. | 10 kN-m/s |
| Answer» B. 1 kN-m | |
| 2502. |
The entropy is a point function and thus it is a property of the same. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 2503. |
When the expansion or compression takes place according to the law pvn = C, the process is known as |
| A. | isothermal process |
| B. | adiabatic process |
| C. | hyperbolic process |
| D. | polytropic process |
| Answer» E. | |
| 2504. |
The state of a substance whose evaporation from its liquid state is complete, is known as |
| A. | vapour |
| B. | perfect gas |
| C. | air |
| D. | steam |
| Answer» C. air | |
| 2505. |
The efficiency of Carnot cycle depends upon |
| A. | temperature limits |
| B. | pressure ratio |
| C. | volume compression ratio |
| D. | cut-off ratio and compression ratio |
| Answer» B. pressure ratio | |
| 2506. |
The gas turbine cycle with regenerator improves |
| A. | thermal efficiency |
| B. | work ratio |
| C. | avoids pollution |
| D. | none of these |
| Answer» B. work ratio | |
| 2507. |
An open system is one in which |
| A. | heat and work crosses the boundary of the system, but the mass of the working substance does not crosses the boundary of the system |
| B. | mass of the working substance crosses the boundary of the system but the heat and work does not crosses the boundary of the system |
| C. | both the heat and work as well as mass of the working substance crosses the boundary of the system |
| D. | neither the heat and work nor the mass of the working substance crosses the boundary of the system |
| Answer» D. neither the heat and work nor the mass of the working substance crosses the boundary of the system | |
| 2508. |
An open cycle gas turbine works on |
| A. | Carnot cycle |
| B. | Otto cycle |
| C. | Joule's cycle |
| D. | Stirling cycle |
| Answer» D. Stirling cycle | |
| 2509. |
The efficiency of Otto cycle depends upon the specific heats of the working substance. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 2510. |
The smallest quantity of a substance, which can exist by itself in a chemically recognizable form is known as |
| A. | element |
| B. | compound |
| C. | atom |
| D. | molecule |
| Answer» E. | |
| 2511. |
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. | |
| 2512. |
The gas constant (R) 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 | |
| 2513. |
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. | |
| 2514. |
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. | |
| 2515. |
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. | |
| 2516. |
The unit of power in S.I. units is kilowatt. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2517. |
Otto cycle consists of |
| A. | two constant volume and two isentropic processes |
| B. | two constant pressure and two isentropic processes |
| C. | two constant volume and two isothermal processes |
| D. | one constant pressure, one constant volume and two isentropic processes |
| Answer» B. two constant pressure and two isentropic processes | |
| 2518. |
The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is always __________ one. |
| A. | equal to |
| B. | less than |
| C. | greater than |
| Answer» D. | |
| 2519. |
Which of the following is the correct statement? |
| A. | For a given compression ratio, both Otto and Diesel cycles have the same efficiency. |
| B. | For a given compression ratio, Otto cycle is more efficient than Diesel cycle. |
| C. | For a given compression ratio, Diesel cycle is more efficient than Otto cycle. |
| D. | The efficiency of Otto or Diessel cycle has nothing to do with compressioin ratio. |
| Answer» C. For a given compression ratio, Diesel cycle is more efficient than Otto cycle. | |
| 2520. |
The temperature at which the volume of a gas becomes zero is called |
| A. | absolute scale of temperature |
| B. | absolute zero temperature |
| C. | absolute temperature |
| D. | none of these |
| Answer» C. absolute temperature | |
| 2521. |
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 | |
| 2522. |
In closed cycle gas turbine, the air is compressed |
| A. | isothermally |
| B. | isentropically |
| C. | polytropically |
| D. | none of these |
| Answer» C. polytropically | |
| 2523. |
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. | |
| 2524. |
The absolute zero pressure will be |
| A. | when molecular momentum of the system becomes zero |
| B. | at sea level |
| C. | at the temperature of - 273 K |
| D. | at the centre of the earth |
| Answer» B. at sea level | |
| 2525. |
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 | |
| 2526. |
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. | |
| 2527. |
The reading of the pressure gauge fitted on a vessel is 25 bar. The atmospheric pressure is 1.03 bar and the value of 'g' is 9.81 m/s2. 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 | |
| 2528. |
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 | |
| 2529. |
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 | |
| 2530. |
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. | |
| 2531. |
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 | |
| 2532. |
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 | |
| 2533. |
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 | |
| 2534. |
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 | |
| 2535. |
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. | |
| 2536. |
One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to |
| A. | 800K |
| B. | 1000K |
| C. | 1200K |
| D. | 1400K |
| Answer» B. 1000K | |
| 2537. |
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 | |
| 2538. |
The efficiency of a gas turbine is given by |
| A. | <img src="/_files/images/mechanical-engineering/thermodynamics/253-233-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/thermodynamics/253-233-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/thermodynamics/253-233-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/thermodynamics/253-233-4.png"> |
| Answer» C. <img src="/_files/images/mechanical-engineering/thermodynamics/253-233-3.png"> | |
| 2539. |
One m3 of methane (CH4) requires 2m3 of oxygen and produces 1m3 of carbon dioxide and 2m3 of water or steam. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 2540. |
Coke oven gas is obtained by burning coke in an oven. |
| A. | Agree |
| B. | Disagree |
| Answer» C. | |
| 2541. |
A perpetual motion machine of the first kind is __________ according to first law of thermodynamics. |
| A. | possible |
| B. | impossible |
| Answer» C. | |
| 2542. |
Which of the following has the highest calorific value? |
| A. | Peat |
| B. | Lignite |
| C. | Bituminous coal |
| D. | Anthracite coal |
| Answer» E. | |
| 2543. |
When a gas is heated, change takes place in |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | all of these |
| Answer» E. | |
| 2544. |
The value of universal gas constant is same for all gases. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 2545. |
The numerical value of the thermal capacity and the water equivalent of the substance are the same. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 2546. |
The value of cp/cv for air is |
| A. | 1 |
| B. | 1.4 |
| C. | 1.8 |
| D. | 23 |
| Answer» C. 1.8 | |
| 2547. |
The state of a substance whose evaporation from its liquid state is partial, is known as steam. |
| A. | Agree |
| B. | Disagree |
| Answer» C. | |
| 2548. |
The general law of expansion or compression is pvn = C, The process is said to be hyperbolic, if n is equal to |
| A. | 0 |
| B. | 1 |
| C. | |
| D. | |
| Answer» C. | |
| 2549. |
The conditions of temperature and pressure at 0 C (273K) and 760 mm of Hg pressure are termed as __________ temperature and pressure. |
| A. | normal |
| B. | standard |
| Answer» C. | |
| 2550. |
The efficiency of Joule cycle is |
| A. | greater than Carnot cycle |
| B. | less than Carnot cycle |
| C. | equal to Carnot cycle |
| D. | none of these |
| Answer» C. equal to Carnot cycle | |