MCQOPTIONS
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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.
| 251. |
Which of the following turbines cannot be set below the maximum tail race level |
| A. | Kaplan |
| B. | Pelton |
| C. | Francis |
| D. | Propeller |
| E. | Energyless process |
| Answer» B. Pelton | |
| 252. |
The number of degrees of freedom for a diatomic molecule is |
| A. | 3 |
| B. | 6 |
| C. | 5 |
| D. | 4 |
| E. | Pulsejet |
| Answer» D. 4 | |
| 253. |
In case the thermal efficiency of an engine becomes 100% it will violate |
| A. | Zeroth law of thermodynamics |
| B. | First law of thermodynamics |
| C. | Second law of thermodynamics |
| D. | Third law of thermodynamics |
| E. | None of the above |
| Answer» D. Third law of thermodynamics | |
| 254. |
On a Mollier chart the flow through turbine is represented by |
| A. | Horizontal line |
| B. | Vertical line |
| C. | Curved line convex up |
| D. | Carved line convex down |
| E. | None of the above |
| Answer» C. Curved line convex up | |
| 255. |
A 500 litre tank contains a saturated mixture of steam and water at 300?C. If the mass of steam and water within the tank is equal, it can be concluded that |
| A. | Steam will be nearly dry and saturated |
| B. | volume of steam will be less than the volume of water |
| C. | Pulsejet |
| D. | Dryness fraction of steam will be closer to 0.5 |
| E. | Volume of steam will be less than the volume of water |
| Answer» F. | |
| 256. |
The fact that the product of pressure and volume of a fixed amount of gas is of approximately constant value is known as |
| A. | Dalton's law |
| B. | None of these |
| C. | Gay Lussac's law |
| D. | Charle's law |
| E. | Lewis law |
| Answer» C. Gay Lussac's law | |
| 257. |
The function of a clutch in automobiles |
| A. | To disengage power from engine to flywheel |
| B. | To disengage power from engine to gear box |
| C. | To disengage power from engine to wheels |
| D. | To absorb power |
| E. | To disengage power from wheels to engine |
| Answer» C. To disengage power from engine to wheels | |
| 258. |
"Heat flows from hot substance to cold substance unaided". The name associated with the above statement is |
| A. | Gay Lussac |
| B. | Joule |
| C. | Clausius |
| D. | Planck |
| E. | Kelvin |
| Answer» D. Planck | |
| 259. |
Which of the following is not a positive displacement compressor? |
| A. | Centrifugal compressor? |
| B. | Vane type compressor |
| C. | Roots blower |
| D. | Double acting reciprocating compressor |
| E. | Single stage reciprocating compressor |
| Answer» B. Vane type compressor | |
| 260. |
Most of gases exhibit drop in temperature upon expansion. However, this may not be true in case of |
| A. | Carbondioxide |
| B. | Hydrogen |
| C. | Helium |
| D. | Oxygen |
| E. | Pulsejet |
| Answer» C. Helium | |
| 261. |
A Brayton cycle is also a reversed |
| A. | Carnot cycle |
| B. | Dual cycle |
| C. | Joule cycle |
| D. | Otto cycle |
| E. | Rankine cycle |
| Answer» D. Otto cycle | |
| 262. |
According to Kinetic theory of gases, at absolute zero |
| A. | Pressure of gas will reduce to zero |
| B. | Mass of gas will reduce to zero |
| C. | Volume of gas will reduce to zero |
| D. | Kinetic energy of gas molecules will reduce to zero |
| E. | Specific heat of molecules will reduce to zero |
| Answer» E. Specific heat of molecules will reduce to zero | |
| 263. |
In a Carnot cycle if isothermal compression process is continued bit longer than the normal, then the adiabatic compression will cause the steam to arrive at the inner dead center at a temperature |
| A. | higher than the normal temperature |
| B. | lower than the normal temperature |
| C. | which is the normal temperature |
| D. | Pulsejet |
| Answer» C. which is the normal temperature | |
| 264. |
According to the Kinetic theory of gases the collision between the molecules are assumed to be |
| A. | Perfectly elastic |
| B. | Partly elastic |
| C. | Partly inelastic |
| D. | 50% elastic |
| E. | Perfectly inelastic |
| Answer» B. Partly elastic | |
| 265. |
All of the following cycles consist of two isentropic processes EXCEPT |
| A. | Otto cycle |
| B. | Stirling cycle |
| C. | Pulsejet |
| D. | Carnot cycle |
| E. | Diesel cycle |
| Answer» C. Pulsejet | |
| 266. |
Which of the following cycle consists of two constant pressure and two adiabatic processes? |
| A. | Carnot cycle |
| B. | Joule cycle |
| C. | Diesel cycle |
| D. | Dual cycle |
| E. | Otto cycle |
| Answer» C. Diesel cycle | |
| 267. |
The extension and compression of a helical spring is an example of |
| A. | Reversible process |
| B. | Adiabatic process |
| C. | Thermodynamic cycle |
| D. | Irreversible process |
| E. | Isothermal process |
| Answer» B. Adiabatic process | |
| 268. |
Triple point temperature and pressure for water are |
| A. | 0.1?C and 0.006028 ata |
| B. | 100?C and 1 ata |
| C. | 0.01?C and 0.006028 ata |
| D. | 0?C and 0.1 ata |
| E. | 0?C 1 ata |
| Answer» D. 0?C and 0.1 ata | |
| 269. |
The concept of black body in heat transfers applies to |
| A. | microns |
| B. | Objects which are black in colour |
| C. | Objects well insulated from surroundings |
| D. | Objects which are good conductors of heat |
| E. | Objects that completely absorb impinging radiation |
| Answer» F. | |
| 270. |
One litre of gas A and two litres of gas B. both having same temperature 100?C and same pressure 2.5 bar will have the ratio of kinetic energies of their molecules as |
| A. | 1 ; 2 |
| B. | 4 ; 1 |
| C. | 1 ; 1 |
| D. | 1 ; 4 |
| E. | Pulsejet |
| Answer» D. 1 ; 4 | |
| 271. |
Thermei is |
| A. | A semi-conductor |
| B. | An impurity added to a semi-conductor |
| C. | A unit of temperature measurement |
| D. | A unit of latent heat |
| E. | Quantity of heat required to raise temperature of one tonne of water from 14.5?C to 15.5?C |
| Answer» F. | |
| 272. |
The efficiency of a Rankine cycle may be expected to |
| A. | Increase with decreasing temperature of heat rejection |
| B. | Decrease with decreasing temperature of heat rejection |
| C. | Decrease with increasing temperature of heat rejection |
| D. | Increase with increasing exhaust pressure |
| E. | None of the above |
| Answer» B. Decrease with decreasing temperature of heat rejection | |
| 273. |
According to Boyle's law PV = C when the temperature is constant. In this relation the magnitude of C depends upon |
| A. | Pulsejet |
| B. | atmospheric pressure |
| C. | atomicity of the gas |
| D. | quantity of the gas involved |
| E. | molecular weight of the gas |
| Answer» E. molecular weight of the gas | |
| 274. |
1 micron is equivalent to |
| A. | 10-2 cm |
| B. | 10-3 cm |
| C. | 10-4 cm |
| D. | 10-6 cm |
| E. | None of the above |
| Answer» D. 10-6 cm | |
| 275. |
A safety valve is used on boilers to |
| A. | Check the level of water |
| B. | Check the level of steam |
| C. | Check the temperature of steam |
| D. | To release excess pressure |
| E. | None of the above |
| Answer» E. None of the above | |
| 276. |
A system consisting of more than one phase is known as |
| A. | Isolated system |
| B. | Closed system |
| C. | Non-uniform system |
| D. | Open system |
| E. | Heterogeneous system |
| Answer» F. | |
| 277. |
For an ideal gas the value of Joule Kelvin coefficient is |
| A. | Negative |
| B. | Unity |
| C. | Infinite |
| D. | Zero |
| E. | 0.5 |
| Answer» E. 0.5 | |
| 278. |
A constant volume gas thermometer closely follows |
| A. | Boyle's law |
| B. | Charle's law |
| C. | Gay Lussac's law |
| D. | None of the above |
| E. | Pulsejet |
| Answer» C. Gay Lussac's law | |
| 279. |
Economiser in the boiler heats the |
| A. | Steam |
| B. | Air |
| C. | Feed water |
| D. | Coal |
| E. | None of the above |
| Answer» D. Coal | |
| 280. |
Avogadro's numbers is |
| A. | 60248.6 x 1026 molecules/(k mol) |
| B. | 6024.86 x 1026 molecules/(k mol) |
| C. | 6.02486 x 1026 molecules/(k mol) |
| D. | 60.2486 x 1026 molecules/(k mol) |
| E. | 602.486 x 1026 molecules/(k mol) |
| Answer» D. 60.2486 x 1026 molecules/(k mol) | |
| 281. |
The function of a distributor is |
| A. | To distribute fuel |
| B. | To distribute spark |
| C. | To time the spark |
| D. | To distribute power |
| E. | To generate the spark |
| Answer» D. To distribute power | |
| 282. |
During constant pressure heating of a gas the following does not increase? |
| A. | Pressure |
| B. | Pulsejet |
| C. | Volume |
| D. | Entropy |
| E. | Temperature |
| Answer» B. Pulsejet | |
| 283. |
The shape of the lid of manhole in a boiler is |
| A. | Circular |
| B. | Elliptical |
| C. | Rectangular |
| D. | Square |
| E. | Special contour |
| Answer» C. Rectangular | |
| 284. |
The rate of discharge through the nozzle |
| A. | remains same |
| B. | decreases |
| C. | increases |
| D. | None of the above |
| Answer» D. None of the above | |
| 285. |
During an adiabatic expansion the increase in volume is associated with |
| A. | Decrease in pressure and decrease in temperature |
| B. | Increase in pressure and decrease in temperature |
| C. | Depends on other factors |
| D. | Increase in pressure and increase in temperature |
| E. | Decrease in pressure and increase in temperature |
| Answer» B. Increase in pressure and decrease in temperature | |
| 286. |
Least value of specific heat |
| A. | Water |
| B. | Ice |
| C. | Alcohol |
| D. | Air |
| E. | Stream |
| Answer» E. Stream | |
| 287. |
In six stage compression of air set for minimum work conditions |
| A. | Pressure rise per stage will be equal |
| B. | Cylinder volumes will be same |
| C. | The discharge pressure will be six times suction pressure |
| D. | Temperature rise in the cylinders will be the same |
| E. | Work done in successive stages will be in geometrical progression |
| Answer» E. Work done in successive stages will be in geometrical progression | |
| 288. |
Which of the following cycle consists of two isothemal and two constant volume processes? |
| A. | Joule cycle |
| B. | Stirling cycle |
| C. | Diesel cycle |
| D. | Rankine cycle |
| E. | Otto cycle |
| Answer» C. Diesel cycle | |
| 289. |
During the boiling of a liquid, which of the following parameter increases? |
| A. | Temperature |
| B. | Free energy |
| C. | Entropy |
| D. | Heat of vaporisation |
| E. | None of the above |
| Answer» D. Heat of vaporisation | |
| 290. |
The triple point of a substance is the temperature and pressure at which |
| A. | The solid and liquid phases are in equilibrium |
| B. | The liquid and gaseous phases are in equilibrium |
| C. | The solid, liquid and the gaseous phases are in equilibrium |
| D. | The solid does not melt, the liquid does not boil and the gas does not condense |
| E. | Temperature shows the extent of expansion |
| Answer» D. The solid does not melt, the liquid does not boil and the gas does not condense | |
| 291. |
In case of ideal monoatomic gas, the ratio of specific heats Cp/Cv would be |
| A. | 1 |
| B. | 1.67 |
| C. | 1.41 |
| D. | 1.4 |
| E. | 1.33 |
| Answer» C. 1.41 | |
| 292. |
The statement that energy can be neigher created nor destroyed but only converted from one form to another, is known as |
| A. | Zerothlaw of thermodynamics |
| B. | Second law of thermodynamics |
| C. | First law of theormodynamics |
| D. | Avogadro's hypothesis |
| E. | Kinetic theory of gases |
| Answer» D. Avogadro's hypothesis | |
| 293. |
The perfect heat engine works on the Carnot cycle between 1000?C and 200?C. The efficiency of the engine will be |
| A. | 60% |
| B. | 68.20% |
| C. | 37.20% |
| D. | 80% |
| E. | 62.80% |
| Answer» F. | |
| 294. |
A wall 50 mm thick (thermal conductivity k = 40 W/m?C) has temperature difference on two surfaces of 100?C. What could probably change if the temperature difference of this wall drops to 100?C |
| A. | Thickness of wall reduces to 5 mm |
| B. | Thickness of wall increases to 500 mm |
| C. | Thermal conductivity changes to 400 W/?C |
| D. | Rate of heat flow drops to one tenth of the original |
| E. | Area of heat transfer increases 10 times |
| Answer» E. Area of heat transfer increases 10 times | |
| 295. |
A Carnot refrigerator extracts 100 kcal of heat per minute from a cold room which is maintained at - 15?C and it is discharged to atmosphere at 30?C. The horse power required to run the unit would be |
| A. | 1 |
| B. | 1.5 to 2 |
| C. | Mone than 6 |
| D. | 2 to 5 |
| E. | 5 to 6 |
| Answer» C. Mone than 6 | |
| 296. |
For any reversible process, the change in entropy of the system and surroundings is |
| A. | Negative |
| B. | Zero |
| C. | Unity |
| D. | Infinite |
| E. | Positive |
| Answer» C. Unity | |
| 297. |
Which of the following introduces irreversibility in the actual Carnot engine operation? |
| A. | Higher operating speeds |
| B. | Losses from working fluid in transit |
| C. | Pulsejet |
| D. | Changes in pressure and temperature during the cycle |
| E. | Friction between moving parts |
| Answer» C. Pulsejet | |
| 298. |
A solar cell system is to suppmy 1050 kWh/month. The average output is 15 percent of the rated power. The rated power must be |
| A. | 4.5 kW |
| B. | Pulsejet |
| C. | 9.7 kW |
| D. | 3 kW |
| E. | 14.4 kW |
| Answer» D. 3 kW | |
| 299. |
If a heat engine gives an output of 3 kW and input is 10,000 J/s the thermal efficiency of the engine will be |
| A. | 70% |
| B. | 30% |
| C. | 33.30% |
| D. | 66.60% |
| E. | 100% |
| Answer» C. 33.30% | |
| 300. |
In a 2 stroke engine we get one power stroke in |
| A. | 180? of crank rotation |
| B. | 540? of crank rotation |
| C. | 360? of crank rotation |
| D. | 270? of crank rotation |
| E. | 720? of crank rotation |
| Answer» D. 270? of crank rotation | |