McqMate
| 301. |
The efficiency of an ideal (Carnot engine) depends on |
| A. | On the temperature of both the source and the sink |
| B. | On the temperature of the source only |
| C. | On the temperature of the sink only |
| D. | On the construction of engine |
| E. | Working substance |
| Answer» A. On the temperature of both the source and the sink | |
| 302. |
A choke is applied in a car |
| A. | For reduction of speed |
| B. | For increasing speed |
| C. | For starting in hot weather |
| D. | For fuel economy |
| E. | For starting in cold weather |
| Answer» E. For starting in cold weather | |
| 303. |
In a reversible polytropic process |
| A. | Some heat transfer occurs |
| B. | Entropy remains constant |
| C. | Enthalpy remains constant |
| D. | Internal energy remains constant |
| E. | None of the above |
| Answer» A. Some heat transfer occurs | |
| 304. |
Rankine cycle efficiency for a power plant is 29.6%. The Carnot cycle efficiency will be |
| A. | Equal to Rankine cycle efficiency |
| B. | More than Rankine cycle efficiency |
| C. | Less than Rankine cycle efficiency |
| D. | There is no comparison for the two |
| E. | None of the above |
| Answer» B. More than Rankine cycle efficiency | |
| 305. |
The heat flows through solids only by |
| B. | Radiation |
| C. | Conduction |
| D. | microns |
| E. | Convection |
| Answer» C. Conduction | |
| 306. |
Sadi Carnot was a |
| A. | French engineer |
| B. | Russian engineer |
| C. | Pulsejet |
| D. | British engineer |
| E. | German engineer |
| Answer» A. French engineer | |
| 307. |
Cut of ratio in a steam engine is the ratio of |
| A. | Work done by piston after cut off to total work done per cylinder |
| B. | Fraction of piston stroke which the piston has travelled when cut off occurs |
| C. | Pressure at cut off to supply pressure |
| D. | Pressure at cut off to exhaust pressure |
| E. | Pressure at cut off to mean effective pressure |
| Answer» B. Fraction of piston stroke which the piston has travelled when cut off occurs | |
| 308. |
Which of the following statement about Vanc der Waal's equation is valid? |
| A. | Pulsejet |
| B. | It represents a straight line on pv versus v plot |
| C. | The equation is valid for diatomic gases only |
| D. | It is valid for all pressures and temperatures |
| E. | It has three roots of identical value at the critical point |
| Answer» E. It has three roots of identical value at the critical point | |
| 309. |
The statement that the volume of a mixture of ideal gases is equal to the span of the partial volumes which the constituent gases would occupy if each existed alone at the pressure and temperature of the mixture, is known as |
| A. | Clapeyrons law |
| B. | Maxwell's law |
| C. | Leduc's law |
| D. | Daltons law |
| E. | Clausius law |
| Answer» C. Leduc's law | |
| 310. |
Two vessels of volume 5 litres and 3 litres contain air at a pressure of 3 atmospheres and 5 atmospheres respectively. When the two vessels are connected together by a small tube (at constant temperature) the reusltant pressure will be |
| A. | 4.0 atm |
| B. | 5.0 atm |
| C. | 4.5 atm |
| D. | 3.75 atm |
| E. | Pulsejet |
| Answer» D. 3.75 atm | |
| 311. |
The rate of radiant energy, which is emitted by a surface at any temperature and in small wavelengths is found from the known rate of energy, which under the same conditions would be emitted from a black surface, by multiplying with the absorptivity. Above enunciation is known as |
| A. | Planck's law |
| B. | Kirchhoff's law |
| C. | Stefan Bolzmann's law |
| D. | Lambart's rule |
| E. | None of the above |
| Answer» B. Kirchhoff's law | |
| 312. |
A gs which satisfies the Kinetic theory of gases is known as |
| A. | Manoatomic gas |
| B. | Diatomic gas |
| C. | Real gas |
| D. | Perfect gas |
| E. | None of the above |
| Answer» D. Perfect gas | |
| 313. |
Which of the following gas will satisfy, Boyle's law over a wider range of temperatures and pressures? |
| A. | Helium |
| B. | Pulsejet |
| C. | Oxygen |
| D. | Hydrogen |
| E. | Carbon monoxide |
| Answer» A. Helium | |
| 314. |
The term "pre-whirl" is associated with |
| A. | Gas turbines |
| B. | Super-charged diesel engines |
| C. | Sliding vane type air compressors |
| D. | Reciprocating air compressors |
| E. | Centrifugal air compressors |
| Answer» E. Centrifugal air compressors | |
| 315. |
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» B. 30% | |
| 316. |
An amount of heat given to a gas under isothermal conditions will be |
| A. | For a temperature rise |
| B. | For doing external work |
| C. | For doing external work and also for a temperature rise |
| D. | For increasing the internal energy of the gas |
| E. | None of the above |
| Answer» B. For doing external work | |
| 317. |
Two gases X and Y having the same temperature T, the same pressure P and the same volume V are mixed. If the mxiture has the volume V and temperature T, then the pressure of the mixture must be |
| A. | 4P |
| B. | P |
| C. | Pulsejet |
| D. | 2P |
| Answer» D. 2P | |
| 318. |
By applying chike in an automobile we get |
| A. | Stoichiometric mixture |
| B. | Chemically correct mixture |
| C. | Weak mixture |
| D. | Lean mixture |
| E. | Rich mixture |
| Answer» E. Rich mixture | |
| 319. |
The critical temperature of carbondioside is 31.1?C. If the room temperature is 34.7?C, then carbondioxide at room temperature is |
| A. | vapour |
| B. | wet vapour |
| C. | Pulsejet |
| D. | superheated vapour |
| E. | gas |
| Answer» E. gas | |
| 320. |
In case of a four cylinder diesel engine, the heat carried away by exhaust gases will be |
| A. | 10 to 20 percent |
| B. | 50 to 70 percent |
| C. | 25 to 35 percent |
| D. | 5 to 7 percent |
| E. | 7 to 10 percent |
| Answer» C. 25 to 35 percent | |
| 321. |
The ratio of enthalpy rise in rotor of a centrifugal compressor to the enthalpy rise in stage is called |
| A. | Adiabatic efficiency |
| B. | Degree of reaction |
| C. | Volumetric efficiency |
| D. | Dynamic pressure ratio |
| E. | Static pressure ratio |
| Answer» B. Degree of reaction | |
| 322. |
During isothermal process |
| A. | Pulsejet |
| B. | supply of heat is accompanied by rise in temperature |
| C. | rise in entropy is accompanied by rise in temperature |
| D. | drop in pressure is accompanied by drop in volume |
| E. | rejection of heat is accompanied by decrease in volume |
| Answer» E. rejection of heat is accompanied by decrease in volume | |
| 323. |
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» C. Change in temperature = Zero | |
| 324. |
Maxwell's thermodynamic relations are valid for |
| A. | Transient conditions only |
| B. | Closed system only |
| C. | Only reversible processes |
| D. | All processes |
| E. | A thermodynamic system in equilibrium |
| Answer» E. A thermodynamic system in equilibrium | |
| 325. |
If during a process, the entropy of the isolated system increases, the process is |
| A. | Adiabatic |
| B. | Ideal |
| C. | Isothermal |
| D. | Reversible |
| E. | Irreversible |
| Answer» E. Irreversible | |
| 326. |
Kelvin's law deals with |
| A. | conservation of work |
| B. | conservation of heat |
| C. | conversion of work into heat |
| D. | conversion of heat into work |
| E. | Pulsejet |
| Answer» D. conversion of heat into work | |
| 327. |
The processes of a Carnot cycle are |
| A. | Two adiabatic and two constant volume |
| B. | Two constant volume and two isothermals |
| C. | Two isothermals and two isentropics |
| D. | Two adiabatics and two isothermals |
| E. | One constant volume one constant pressure and two isentropics |
| Answer» C. Two isothermals and two isentropics | |
| 328. |
Theoretically in a petrol engine during which stroke both suction as well as exhaust valves will remain closed? |
| A. | Suction stroke |
| B. | Exhaust stroke |
| C. | Both suction and exhaust strokes |
| D. | None of the above |
| E. | Pulsejet |
| Answer» D. None of the above | |
| 329. |
Wavelength is generally measured in |
| A. | microns |
| B. | mm |
| C. | km |
| D. | m |
| E. | cm |
| Answer» A. microns | |
| 330. |
The unit of Universal Gas constant is |
| A. | Dynes/?K |
| B. | erg/?K |
| C. | kcal/?K |
| D. | It is dimensionless |
| E. | W/m?K |
| Answer» B. erg/?K | |
| 331. |
Pipes are insulated so that |
| A. | They may not break under pressure |
| B. | There is minimum corrosion |
| C. | Capacity to withstand pressure is increased |
| D. | Heat loss from the surface is minimized |
| E. | None of the above |
| Answer» D. Heat loss from the surface is minimized | |
| 332. |
The process that follows the equation pvn = constant, is called |
| A. | Adiabatic process |
| B. | Constant pressure process |
| C. | Constant volume process |
| D. | Constant temperature process |
| E. | Polytropic process |
| Answer» E. Polytropic process | |
| 333. |
The total radiant energy emitted by a plane surface per unit area and unit time is called |
| A. | Radiant flux density |
| B. | Total absorptivity |
| C. | Radiant energy |
| D. | Radiant intensity |
| E. | None of the above |
| Answer» A. Radiant flux density | |
| 334. |
Maxwells relations are valid for |
| A. | compressible substances |
| B. | all substances solid, liquid or gas |
| C. | systems of fixed chemical compositions |
| D. | Pulsejet |
| E. | homogeneous as well as heterogeneous systems |
| Answer» A. compressible substances | |
| 335. |
Clog point of an oil is |
| A. | The point of maximum contamination of oil |
| B. | The level of impurities beyond which oil ceases to flow |
| C. | The temperature at which oil solidifies |
| D. | The temperature at which paraffin and waxes in oil start precipitating |
| E. | None of the above |
| Answer» D. The temperature at which paraffin and waxes in oil start precipitating | |
| 336. |
Line's liquifer is based on the principle of |
| A. | Pulsejet |
| B. | Joule-Thomson effect |
| C. | adiabatic magnetisation |
| D. | adiabatic expansion |
| E. | adiabatic demagnetisation |
| Answer» D. adiabatic expansion | |
| 337. |
A process which does not dissipate available energy is known as |
| A. | Adiabatic process |
| B. | Frictionless process |
| C. | Isothermal process |
| D. | Energyless process |
| E. | Ideal process |
| Answer» E. Ideal process | |
| 338. |
Gas laws are applicable to |
| A. | Gases and dry, wet and super-heated vapours |
| B. | Gases only |
| C. | Gases and dry and wet vapours |
| D. | Gases and wet vapours |
| E. | Gases and dry vapours |
| Answer» B. Gases only | |
| 339. |
In an optimum four stage compressor system the first and third stage pressure are 1 kg/cm2 and 9 kg/cm2 respectively what will be the fourth stage delivery pressure? |
| A. | 81 kg/cm2 |
| B. | 27 kg/cm2 |
| C. | 9 kg/cm2 |
| D. | 6 kg/cm2 |
| E. | 3 kg/cm2 |
| Answer» A. 81 kg/cm2 | |
| 340. |
In unsteady state, heat transfer occurs when |
| A. | The body through which heat flow is in motion |
| B. | The source of heat is in motion |
| C. | The heat flow changes with change in temperature |
| D. | The heat flow changes with time |
| E. | None of the above |
| Answer» D. The heat flow changes with time | |
| 341. |
At critical point the latent enthalpy of vaporisation is |
| A. | Only depends on temperature |
| B. | Zero |
| C. | Maximum |
| D. | Minimum |
| E. | None of the above |
| Answer» B. Zero | |
| 342. |
Which of the following relation is not valid for throttling process? |
| A. | Enthalpy before expansion = Enthalpy after expansion |
| B. | Pressure before expansion = pressure after expansion |
| C. | External work done = Zero |
| D. | Mass before expansion = mass after expansion |
| E. | None of the above |
| Answer» B. Pressure before expansion = pressure after expansion | |
| 343. |
The specific heat of a perfect gas is a function of |
| A. | temperature, pressure and entropy only |
| B. | temperature only |
| C. | temperature and pressure only |
| D. | Pulsejet |
| E. | temperature and entropy only |
| Answer» B. temperature only | |
| 344. |
One watt is the same as |
| A. | 100 Nm/s |
| B. | 10 Nm/s |
| C. | 1 Nm/s |
| D. | 1 Nm/min |
| E. | 10 Nm/min |
| Answer» C. 1 Nm/s | |
| 345. |
Within the boiler, the temperature of steam is highest in |
| A. | Super heater |
| B. | Temperature remains constant |
| C. | Water walls |
| D. | Water drum |
| E. | Water tubes |
| Answer» A. Super heater | |
| 346. |
The rate of diffusion along a column of certain cross-sectional area is proportional to the concentration gradient. Above statement is known as |
| A. | Thompson's law |
| B. | Law of diffusion |
| C. | Kirchhoff's law |
| D. | Fick's law |
| E. | None of the above |
| Answer» D. Fick's law | |
| 347. |
1 kgf/cm2 is equal to |
| A. | 776 mm Hg |
| B. | 1 mm Hg |
| C. | 760 mm Hg |
| D. | 735.6 mm Hg |
| E. | 100 mm Hg |
| Answer» D. 735.6 mm Hg | |
| 348. |
If molar Cp = 4.97 then |
| A. | Cv = 2.97 |
| B. | Cv = 0.97 |
| C. | Cv = 5.97 |
| D. | Cv = 0.597 |
| E. | Cv = 1.97 |
| Answer» A. Cv = 2.97 | |
| 349. |
The value of the product of molecular weight and the gas characteristic constant for all gases in kgf m/1 kg mol ?K is |
| A. | 848 |
| B. | 427 |
| C. | 770 |
| D. | 29.27 |
| E. | 30 |
| Answer» B. 427 | |
| 350. |
Isentropic flow is |
| A. | Perfect gas flow |
| B. | Reversible adiabatic flow |
| C. | Ideal fluid flow |
| D. | Irreversible adiabatic flow |
| E. | Frictionaless reversible flow |
| Answer» B. Reversible adiabatic flow | |
| 351. |
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» A. 7.7 kJ | |
| 352. |
Second law of theromodynamics defines |
| A. | Heat |
| B. | Entropy |
| C. | Work |
| D. | Internal energy |
| E. | Enthalpy |
| Answer» B. Entropy | |
| 353. |
In a reversible polytropic process |
| A. | The entropy remains constant |
| B. | Enthalpy remains constant |
| C. | Internal energy remains constant |
| D. | Some heat transfer occurs |
| E. | Temperature remains constant |
| Answer» D. Some heat transfer occurs | |
| 354. |
Entropy of the universe tends to |
| A. | Approximately zero |
| B. | A minimum |
| C. | A maximum |
| D. | No particular value as it remains constant |
| E. | Zero |
| Answer» C. A maximum | |
| 355. |
Isothermals are curves obtained by drawing |
| A. | P against T |
| B. | P against V |
| C. | V against T |
| D. | PV against T |
| E. | PV against V |
| Answer» B. P against V | |
| 356. |
In an isothermal expansion of gases |
| A. | Temperature is lowered |
| B. | Temperature shows the extent of expansion |
| C. | Temperature becomes zero |
| D. | Temperature is unaltered |
| E. | Temperature is raised |
| Answer» D. Temperature is unaltered | |
| 357. |
A machine that continuously creates its own energy is known as |
| A. | Perpetual motion machine of second kind |
| B. | Self-propelled machine |
| C. | 100% efficient machine |
| D. | Perpetual motion machine of first kind |
| E. | Reversible machine |
| Answer» D. Perpetual motion machine of first kind | |
| 358. |
When a direct current is passed through a junction of two dissimilar metals, the junction becomes either cold or hot. The phenomenon is known as |
| A. | Faraday's law |
| B. | Peltier's effect |
| C. | Thompson effect |
| D. | Maxwell's effect |
| E. | Seeback's effect |
| Answer» B. Peltier's effect | |
| 359. |
Brayton cycle cannot be used in reciprocating engines even for same adiabatic compression ratio and work output because |
| A. | Brayton cycle is for slow speed engines |
| B. | Brayton cycle is less efficient |
| C. | Brayton cycle requires large air-fuel ratio |
| D. | Otto cycle is more efficient |
| E. | Large volume of low pressure air cannot be efficiently handled in reciprocating engines |
| Answer» E. Large volume of low pressure air cannot be efficiently handled in reciprocating engines | |
| 360. |
Which of the following relations is not valid during throttling process? |
| A. | External work done = Zero |
| B. | Total heat = Constant |
| C. | Pressure drop = Zero |
| D. | Change in enthalpy = Zero |
| E. | Change in internal energy = Zero |
| Answer» C. Pressure drop = Zero | |
| 361. |
Two ideal engines A and B have their sources at 600 k and 400 k and their sinks at 300 k and 250 k respectively. What inference can be drawn about their efficiency |
| A. | A is more efficient than B |
| B. | A is less efficient than B |
| C. | The information given is incomplete |
| D. | Both are equally efficient |
| E. | Pulsejet |
| Answer» A. A is more efficient than B | |
| 362. |
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» B. Roult's law | |
| 363. |
A barn is |
| A. | A unit of area |
| B. | A unit of length |
| C. | A unit of time |
| D. | A unit of mass |
| E. | None of the above |
| Answer» A. A unit of area | |
| 364. |
Highly polished surfaces of a thermosflask prevent heat by |
| B. | Convection |
| C. | Radiation |
| D. | Conduction |
| E. | microns |
| Answer» C. Radiation | |
| 365. |
As we go up in air the temperature of air decreases because |
| A. | Pulsejet |
| B. | winds help in heat transfer by convection |
| C. | of low pressure of air |
| D. | oxygen content of air decreases sharply |
| E. | heating effect due to infra red radiations from the surface of the earth is reduced |
| Answer» E. heating effect due to infra red radiations from the surface of the earth is reduced | |
| 366. |
According to kinetic theory of heat |
| A. | Temperature should rise during boiling |
| B. | Temperature should fall during freezing |
| C. | At low temperatures all bodies are in solid state |
| D. | At absolute zero there is absolute no vibration of molecules |
| E. | None of the above |
| Answer» D. At absolute zero there is absolute no vibration of molecules | |
| 367. |
Balanced draft incorporates |
| A. | Forced draft |
| B. | Induced draft |
| C. | Forced and induced draft |
| D. | Chimney draft only |
| E. | None of the above |
| Answer» C. Forced and induced draft | |
| 368. |
The internal energy of an ideal gas is |
| A. | A function of temperature alone |
| B. | A function of pressure |
| C. | A function of volume |
| D. | (a) and (b) only |
| E. | All the above |
| Answer» A. A function of temperature alone | |
| 369. |
In any process the maximum amount of mechanical energy that can be converted to heat |
| A. | Depends upon the intake and exhaust temperature |
| B. | Is 50% |
| C. | Depends upon the amount of friction |
| D. | Depends upon whether kinetic energy is involved |
| E. | Is 100% |
| Answer» E. Is 100% | |
| 370. |
The characteristic equation of gases pv = nRT holds good for |
| A. | Real gases |
| B. | Monoatomic gases |
| C. | Diatomic gases |
| D. | Ideal gases |
| E. | Mixture of gases |
| Answer» A. Real gases | |
| 371. |
The external work donw is zero all the following cases EXCEPT |
| A. | Pulsejet |
| B. | Constant volume |
| C. | Isothermal |
| D. | Free expansiton |
| E. | Throttling |
| Answer» C. Isothermal | |
| 372. |
If a process can be stopped at any stage and reversed so that the system and surroundings are exactly restored to their initial states, it is known as |
| A. | Isothermal process |
| B. | Thermodynamic process |
| C. | Ideal process |
| D. | Adiabatic process |
| E. | Reversible process |
| Answer» E. Reversible process | |
| 373. |
Which of the following does not change during an-ideal throttling process? |
| A. | Pressure, volume and temperature |
| B. | Enthalpy |
| C. | Pressure and volume |
| D. | Temperature and pressure |
| E. | Enthalpy and temperature |
| Answer» B. Enthalpy | |
| 374. |
The process in which no heat enters or leaves the system is called |
| A. | Isobaric |
| B. | Isothermal |
| C. | Isentropic |
| D. | Isochoric |
| E. | None of the above |
| Answer» C. Isentropic | |
| 375. |
Which is incorrect statement about the reversible process? |
| A. | A reversible process is ideal |
| B. | A reversible process must pass through a continuous series of equilibrium states |
| C. | A reversible process when undone, will leave no history of the events in the surroundings |
| D. | A reversible process must pass through the same states on the reversed path as were initially visited on the forward path |
| E. | None of the above |
| Answer» E. None of the above | |
| 376. |
For water which of the following will be reduced to zero at critical pressure? |
| A. | Specific volume |
| B. | Enthalpy |
| C. | Internal energy |
| D. | Latent heat of vaporisation |
| E. | None of the above |
| Answer» D. Latent heat of vaporisation | |
| 377. |
In case of centrifugal compressors, the phenomenon of air stream not able to follow the blade contour of an axial compressor is known as |
| A. | Stalling |
| B. | Feedback |
| C. | Regeneration |
| D. | Recirculation |
| E. | Surging |
| Answer» A. Stalling | |
| 378. |
If the rate of heat flow in aboves case remains constant, the ratio of temperature difference (?t1) (?t2) would be |
| A. | 16 ; 1 |
| B. | 1 ; 4 |
| C. | 8 ; 1 |
| D. | 1 ; 16 |
| E. | 1 ; 8 |
| Answer» A. 16 ; 1 | |
| 379. |
The ratio of heat flow QA/QB from two walls of same thickness having thermal conductivity kA = 2 kB, for the same temperature difference will be |
| A. | 1 |
| C. | 2 |
| D. | 0.5 |
| E. | None of the above |
| Answer» C. 2 | |
| 380. |
Adiabatic bulk modulus is Y times the isothermal bulk modulus |
| A. | Pulsejet |
| B. | for liquids only |
| C. | for real gases only |
| D. | for perfect gases only |
| E. | for all fluids |
| Answer» E. for all fluids | |
| 381. |
A fusible plug is utilised when |
| A. | Impurities in water are excessive |
| B. | Water level is too low |
| C. | Water level is too high |
| D. | Firing rate is high |
| E. | Steam generation rate is high |
| Answer» B. Water level is too low | |
| 382. |
A carnot cycle engine operating between temperature range of 50?C and 100?C will have the efficiency of nearly |
| A. | 50% |
| B. | 26.80% |
| C. | 13.40% |
| D. | Pulsejet |
| E. | 40% |
| Answer» C. 13.40% | |
| 383. |
Free piston engines find application in |
| A. | Compression air supply |
| B. | Mining installation |
| C. | Gas turbines |
| D. | supercharging reciprocating engines |
| E. | None of the above |
| Answer» C. Gas turbines | |
| 384. |
For a pure substance at its triple point, the number of degrees of freedom is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | None of the above |
| E. | Pulsejet |
| Answer» A. 0 | |
| 385. |
A control volume refers to |
| A. | An isolated system |
| B. | A specified mass |
| C. | A fixed region in space |
| D. | A closed system |
| E. | A reversible process only |
| Answer» C. A fixed region in space | |
| 386. |
In an adiabatic change the system |
| A. | Heat taken from surroundings is exactly equal to heat rejected to surroundings |
| B. | Exchanges no heat with the surroundings |
| C. | Gives heat to the surrounding |
| D. | Partly takes heat and partly leaves to the surroundings |
| E. | Takes heat from the surroundings |
| Answer» B. Exchanges no heat with the surroundings | |
| 387. |
In case of axial flow compressors for minimum fluid driction and blade tip clearance losses, the blades of an axial flow compressor are disigned for |
| A. | 53% reaction |
| B. | 90% reaction |
| C. | 60% reaction |
| D. | Less than 50% reaction |
| E. | 75% reaction |
| Answer» A. 53% reaction | |
| 388. |
If the temperature of the source is increased, the efficiency of the Carnot engine |
| A. | Will be equal to the efficiency of a practical engine |
| B. | Increases |
| C. | Does not change |
| D. | Depends on their factors |
| E. | Decreases |
| Answer» B. Increases | |
| 389. |
In Porous plug experiment the change in temperature of a gas depends upon |
| A. | its molecular weight |
| B. | its specific heat |
| C. | pressure gradient on either side |
| D. | All of the above |
| E. | Pulsejet |
| Answer» C. pressure gradient on either side | |
| 390. |
"What two dissimilar metals are heated at one end cooled at the other c.m.f. is developed proportional to difference of temperatures at two ends". Which of the following name is associated with the above statement? |
| A. | Euler |
| B. | Peltier-Thomson |
| C. | Gay-Lussac |
| D. | Faraday |
| E. | Kelvin-planck |
| Answer» B. Peltier-Thomson | |
| 391. |
Which two cycles have one constant volume, one constant pressure and two adiabatic processes each? |
| A. | Brayton and Joules cycle |
| B. | Diesel and Dual cycles |
| C. | Otto and Carnot cycles |
| D. | Sterling and Diesel cycles |
| E. | Pulsejet |
| Answer» D. Sterling and Diesel cycles | |
| 392. |
If the door of a refrigerator in a room is left open, the temperature of the room will |
| A. | decrease |
| B. | Pulsejet |
| C. | remain unaltered |
| E. | increase |
| Answer» E. increase | |
| 393. |
For the same heat inpur and same compression ratio |
| A. | Otto cycle and Diesel cycle are equally efficient |
| B. | Otto cycle is less efficient than diesel cycle |
| C. | Efficiency depends mainly on working substance |
| D. | None of the above |
| E. | Rankine |
| Answer» D. None of the above | |
| 394. |
In case of six stage compression of air for minimum work conditions |
| A. | Pressure rise per stage will be equal |
| B. | Cylinder volumes will be identical |
| C. | Temperature rise in the cylinders will be the same |
| D. | Work done in successive stages will be in geometrical progression |
| E. | Piston diameters will be identical |
| Answer» D. Work done in successive stages will be in geometrical progression | |
| 395. |
The value of characteristic gas constant in kg metre per kg per deg C as |
| A. | 29.97 |
| B. | 1554 |
| C. | 848 |
| D. | 96 |
| E. | 53.3 |
| Answer» A. 29.97 | |
| 396. |
The processes or systems that do not involve heat are called |
| A. | Adiabatic processes |
| B. | Steady processes |
| C. | Equilibrium processes |
| D. | Thermal processes |
| E. | Isothermal processes |
| Answer» A. Adiabatic processes | |
| 397. |
The vapour pressure of water at 30?C in pascals is |
| A. | 0.44 |
| B. | 4315 |
| C. | 223 |
| D. | 431.5 |
| E. | 7.18 |
| Answer» B. 4315 | |
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