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MCQOPTIONS
This section includes 430 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 401. |
In which case the work done per kg of air compressed from 1.05 ata, 15?C to 6.3 ata is minimum |
| A. | Polytropic with index n = 1.35 |
| B. | Adiabatic |
| C. | Polytropic with index n = 1.40 |
| D. | Isothermal |
| E. | Polytropic with index n = 1.3 |
| Answer» E. Polytropic with index n = 1.3 | |
| 402. |
The process during which external work done is not zero, is |
| A. | Constant volume process |
| B. | Constant pressure process |
| C. | Throttling |
| D. | Free expansion |
| E. | All of the above |
| Answer» C. Throttling | |
| 403. |
In the above problem work done is equal to |
| A. | 130 kcal |
| B. | 150 kcal |
| C. | 100 kcal |
| D. | 80 kcal |
| E. | 180 kcal |
| Answer» E. 180 kcal | |
| 404. |
When a gas expands in a closed vessel, the maximum work will be done when the process is at constant |
| A. | Pressure |
| B. | Enthalpy |
| C. | Volume |
| D. | Entropy |
| E. | Temperature |
| Answer» B. Enthalpy | |
| 405. |
An elastic sphere of 0.5 m diameter contains a gas at 115 k Pa. Heating of the sphere causes it to increase to 0.62 m and during the process the pressure is proportional to the sphere diameter. The work done by the gas will be |
| A. | 7.7 kJ |
| B. | Pulsejet |
| C. | 9.9 kJ |
| D. | 15 kJ |
| E. | 11 kJ |
| Answer» B. Pulsejet | |
| 406. |
Which of the following relations is not applicable to free expansion process? |
| A. | Heat supplied = Zero |
| B. | Change in internal energy = Zero |
| C. | Change in temperature = Zero |
| D. | Heat rejected = Zero |
| E. | Work done = Zero |
| Answer» D. Heat rejected = Zero | |
| 407. |
A law which is applicable only to ideal vapours and liquids, that equates the equilibrium partial pressures of a solution component in the coexisting phases, is known as |
| A. | Maxwell's equation |
| B. | Roult's law |
| C. | Henry's law |
| D. | Fick's law |
| E. | Joule's law |
| Answer» C. Henry's law | |
| 408. |
In a thermal power plant thermodynamic cycle used is |
| A. | Joule |
| B. | Brayton |
| C. | Carnot |
| D. | Erricson |
| E. | Rankine |
| Answer» F. | |
| 409. |
The statement that the entropy of a pure substance in complete theromodynamic equilibrium becomes zero at the absolute zero of temperature is known as |
| A. | First law of thermodynamics |
| B. | Third law of thermodynamics |
| C. | Law of entropy |
| D. | Zeroth law of thermodynamics |
| E. | Second law of thermodynamics |
| Answer» C. Law of entropy | |
| 410. |
During an adiabatic expansion, the increase in volume is associated with |
| A. | decrease in pressure and increase in temperature |
| B. | increase in pressure and decrease in temperature |
| C. | Decrease in pressure and decrease in temperature |
| D. | Pulsejet |
| E. | increase in pressure and increase in temperature |
| Answer» D. Pulsejet | |
| 411. |
Which one of the following is an indirect reaction device? |
| A. | Turbojet |
| B. | Ramjet |
| C. | Pulsejet |
| D. | Propeller |
| E. | All of the above |
| Answer» E. All of the above | |
| 412. |
A surface which diffusely reflects and emits tha same amount of energy which it receives by radiation, is known as |
| A. | A perfect surface |
| B. | A perfect grey surface |
| C. | A perfect white surface |
| D. | A perfect radiating surface |
| E. | None of the above |
| Answer» E. None of the above | |
| 413. |
A gas (inversion temperature Ti) undergoing Joule Thomson expansion at temperature T will produce cooling effect only when |
| A. | Ti < T |
| B. | Ti > T |
| C. | Pulsejet |
| D. | Ti = T |
| Answer» C. Pulsejet | |
| 414. |
Food can be cooked quicker in a pressure cooker because |
| A. | Less heat is lost |
| B. | High pressure steam has high temperature |
| C. | Steam remains within the cooker |
| D. | It is made of a metal |
| E. | None of the above |
| Answer» D. It is made of a metal | |
| 415. |
The value of universal gas constant in S.I. units is |
| A. | 831.4 J/kg mole/?k |
| B. | 8314 J/kg mole/?k |
| C. | 8.314 J/kg mole/?k |
| D. | 83.14 J/kg mole/?k |
| E. | 0.8314 J/kg mole/?k |
| Answer» C. 8.314 J/kg mole/?k | |
| 416. |
At critical point the enthalpy of vaporisation is |
| A. | Only dependent on temperature |
| B. | Zero |
| C. | Maximum |
| D. | Minimum |
| E. | None of the above |
| Answer» C. Maximum | |
| 417. |
Exhaust gases from a engine possess |
| A. | Chemical energy |
| B. | Solar energy |
| C. | Potential energy |
| D. | Stored energy |
| E. | Kinetic energy |
| Answer» F. | |
| 418. |
The number of degrees of freedom in case of triatomic gases is |
| A. | 5 |
| B. | 3 |
| C. | 6 |
| D. | 4 |
| E. | 2 |
| Answer» D. 4 | |
| 419. |
Non-dimensional numbers generally involved in case of heat transfer from horizontal cylinders by natural convection are |
| A. | Reynolds number |
| B. | Nusselt number |
| C. | Prandtl number |
| D. | Grashof number |
| E. | (B), (C) and (D) above |
| Answer» F. | |
| 420. |
In a Carnot cycle the heat is rejected at |
| A. | Constant pressure |
| B. | Constant temperature |
| C. | Constant entropy |
| D. | Constant enthalpy |
| E. | Constant volume |
| Answer» C. Constant entropy | |
| 421. |
The mean free path of a gas least depends on |
| A. | volume of gas |
| B. | viscosity of gas |
| C. | Pulsejet |
| D. | density of gas |
| E. | pressure of gas |
| Answer» B. viscosity of gas | |
| 422. |
If a system neither exchange mass nor energy with the surroundings, it is known as |
| A. | Semi-closed system |
| B. | Isolated system |
| C. | Inactive system |
| D. | Closed system |
| E. | Segregated system |
| Answer» C. Inactive system | |
| 423. |
The mean free path of a gas molecule increases with |
| A. | increase in pressure |
| B. | increase in density |
| C. | increase in temperature |
| D. | Pulsejet |
| E. | decrease in temperature |
| Answer» D. Pulsejet | |
| 424. |
In which of the following case the process of sublimation can occur? |
| A. | Solid nitrogen |
| B. | Solid carbondioxide |
| C. | Liquid air |
| D. | Solid oxygen |
| E. | Sodium |
| Answer» C. Liquid air | |
| 425. |
Which of the following cycle is less efficient as compared to the remaining? |
| A. | Carnot cycle |
| B. | All have identical efficiency |
| C. | Stirling cycle |
| D. | Ericsson cycle |
| E. | Otto cycle |
| Answer» F. | |
| 426. |
Which of the following valve is installed between the boiler and the feed pump? |
| A. | Flow of cock |
| B. | Pulsejet |
| C. | Steam stop valve |
| D. | Throttle valve |
| E. | Feed check valve |
| Answer» F. | |
| 427. |
Power required for the engine is |
| A. | 7.75 kW |
| B. | 8.88 kW |
| C. | 9.23 kW |
| D. | 6.60 kW |
| E. | Pulsejet |
| Answer» D. 6.60 kW | |
| 428. |
Which of the following is a reversible process? |
| A. | Extension and compression of a spring |
| B. | Diffusion |
| C. | Free expansion |
| D. | Throttling |
| E. | Combustion |
| Answer» B. Diffusion | |
| 429. |
Cetane number of a diesel fuel is a measure of its |
| A. | volatility |
| B. | Pulsejet |
| C. | delay period |
| D. | viscosity |
| E. | ignition quality |
| Answer» F. | |
| 430. |
Thermodynamic equilibrium is completely defined by the specifications of |
| A. | Internal energy |
| B. | Enthalpy |
| C. | Generalized displacements |
| D. | All the above together |
| E. | None of the above |
| Answer» E. None of the above | |