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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 2501. |
If the thermal conductivity of a wall material is independent of temperature, the steady state temperature distribution in the very large thin plane wall having steady, uniform surface temperature follows __________ law. |
| A. | hyperbolic |
| B. | parabolic |
| C. | linear |
| D. | logarithmic |
| Answer» D. logarithmic | |
| 2502. |
In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred |
| A. | through a metallic wall. |
| B. | by direct contact of hot flue gas with air. |
| C. | by heating an intermediate material (like chequor bricks) and then heating the air from this hot material. |
| D. | none of these. |
| Answer» D. none of these. | |
| 2503. |
Grashoff number, which is defined as g . (Ts - T ) 2. L3/ 2, is proportional to the ratio of buoyancy force to __________ force. |
| A. | viscous |
| B. | elastic |
| C. | inertial |
| D. | none of these |
| Answer» B. elastic | |
| 2504. |
Graetz number is given by |
| A. | <img src="/_files/images/chemical-engineering/heat-transfer/233-20-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/heat-transfer/233-20-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/heat-transfer/233-20-3.png"> |
| D. | <img src="/_files/images/chemical-engineering/heat-transfer/233-20-2.png"> |
| Answer» B. <img src="/_files/images/chemical-engineering/heat-transfer/233-20-2.png"> | |
| 2505. |
For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in |
| A. | increased economy |
| B. | decreased economy |
| C. | lower capacity |
| D. | no effect on economy |
| Answer» B. decreased economy | |
| 2506. |
Economy of an evaporator is influenced by the |
| A. | steam pressure |
| B. | feed temperature |
| C. | number of effect |
| D. | both(b) & (c) |
| Answer» E. | |
| 2507. |
In a 1-1 cocurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is |
| A. | |
| B. | 0 |
| C. | equal to the difference between hot and cold fluids inlet temperature. |
| D. | equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature. |
| Answer» C. equal to the difference between hot and cold fluids inlet temperature. | |
| 2508. |
A body is called grey if the monochromatic emissivity of the body is |
| A. | zero |
| B. | unity |
| C. | same for all wavelengths |
| D. | different for all wavelengths |
| Answer» D. different for all wavelengths | |
| 2509. |
In an extended surface heat exchanger, fluid having lower co-efficient |
| A. | flows through the tube. |
| B. | flows outside the tubes. |
| C. | can flow either inside or outside the tubes. |
| D. | should not be used as it gives very high pressure drop. |
| Answer» C. can flow either inside or outside the tubes. | |
| 2510. |
In a shell and tube heat exchanger, the tube side heat transfer co-efficient just at the entrance of the tube is |
| A. | infinity. |
| B. | zero. |
| C. | same as average heat transfer co-efficient for tube side. |
| D. | none of these. |
| Answer» B. zero. | |
| 2511. |
The equivalent diameter for the annulus of a double pipe heat exchanger, whose inner pipe has fins on the outside is __________ compared to the same size pipes without fins. |
| A. | more |
| B. | less |
| C. | same |
| D. | unpredictable |
| Answer» C. same | |
| 2512. |
Natural convection is characterised by |
| A. | Grashhoff number |
| B. | Peclet number |
| C. | Reynolds number |
| D. | Prandtl number |
| Answer» B. Peclet number | |
| 2513. |
Nusselt number for full developed, laminar, constant property flow in a pipe at uniform heat flux is |
| A. | 0.72 |
| B. | 4.364 |
| C. | 18 |
| D. | 83 |
| Answer» C. 18 | |
| 2514. |
Heat transfer efficiency leading of energy conservation in a heat exchanger can be achieved by |
| A. | keeping the heat transfer surface clean. |
| B. | enhancing the fluid pumping rate. |
| C. | increasing the tube length. |
| D. | none of these. |
| Answer» B. enhancing the fluid pumping rate. | |
| 2515. |
Trap is used to remove __________ from steam pipe lines. |
| A. | steam |
| B. | condensate |
| C. | non-condensables |
| D. | none of these |
| Answer» C. non-condensables | |
| 2516. |
A composite flat wall of a furnace is made of two materials 'A' and 'B'. The thermal conductivity of 'A' is twice of that of material 'B', while the thickness of layer of 'A' is half that of B. If the temperature at the two sides of the wall are 400 and 1200 K, then the temperature drop (in K) across the layer of material 'A' is |
| A. | 125 |
| B. | 133 |
| C. | 150 |
| D. | 160 |
| Answer» E. | |
| 2517. |
Thickness of thermal boundary layer is more compared to that of hydrodynamic boundary layer, when the value of Prandtl number is |
| A. | 1 |
| B. | < 1 |
| C. | > 1 |
| D. | > 5 |
| Answer» C. > 1 | |
| 2518. |
Tube pitch is the __________ of tube diameters and the clearances. |
| A. | sum |
| B. | difference |
| C. | ratio |
| D. | none of these |
| Answer» B. difference | |
| 2519. |
With increase in the distance between the heat source and the object receiving the heat, the radiation heat transfer |
| A. | decreases |
| B. | increases |
| C. | increases exponentially |
| D. | remains unaffected |
| Answer» B. increases | |
| 2520. |
Which of the following remains constant during sensible cooling process ? |
| A. | Specific humidity |
| B. | Partial pressure of vapour |
| C. | Both (a) and (b) |
| D. | Neither (a) nor (b) |
| Answer» D. Neither (a) nor (b) | |
| 2521. |
When warm and cold liquids are mixed, the heat transfer is mainly by |
| A. | conduction |
| B. | convection |
| C. | radiation |
| D. | both(a) & (c) |
| Answer» C. radiation | |
| 2522. |
As the reflux ratio in a distillation coloumn is increased from the minimum, the |
| A. | slope of the operating line in stripping section decreases. |
| B. | number of plates decreases very slowly first and then more and more rapidly. |
| C. | total cost first decreases and then increases. |
| D. | liquid flow increases while the vapor flow decreases for a system. |
| Answer» D. liquid flow increases while the vapor flow decreases for a system. | |
| 2523. |
A plait point is the point on the solubility curve, where the tie line reduces to a point. What is the number of plait point for a ternery system containing twopairs of partially miscible liquids ? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» B. 1 | |
| 2524. |
Physical absorption is |
| A. | an irreversible phenomenon. |
| B. | a reversible phenomenon. |
| C. | accompanied by evolution of heat. |
| D. | both (b) and (c) |
| Answer» E. | |
| 2525. |
Relative humidity is the ratio of the |
| A. | partial pressure of the vapour to the vapour pressure of the liquid at room temperature. |
| B. | partial pressure of the vapour to the vapour pressure of the liquid at gas temperature. |
| C. | actual humidity to saturation humidity. |
| D. | none of these |
| Answer» C. actual humidity to saturation humidity. | |
| 2526. |
In batch distillation with constant reflux, overhead product composition __________ with time. |
| A. | increases |
| B. | decreases |
| C. | does not vary |
| D. | may increase on decrease, depends on the system. |
| Answer» C. does not vary | |
| 2527. |
Psychrometry deals with the properties of gas-vapor mixture. Humidity can be determined by the measurement of the __________ of a fibre. |
| A. | electrical resistance |
| B. | thermal conductivity |
| C. | strength |
| D. | none of these. |
| Answer» B. thermal conductivity | |
| 2528. |
Heat in BTU necessary to increase the temperature of 1 lb of gas and its accompanying vapour by 1 F is called the |
| A. | latent heat |
| B. | humid heat |
| C. | specific heat |
| D. | sensible heat |
| Answer» D. sensible heat | |
| 2529. |
Drying operation under vacuum is carried out to |
| A. | dry those materials which have very high unbound mositure content. |
| B. | reduce drying temperature. |
| C. | increase drying temperature. |
| D. | dry materials having high bound moisture content. |
| Answer» C. increase drying temperature. | |
| 2530. |
Air initially at 101. 3 kPa and 40 C and with a relative humidity of 50%, is cooled at constant pressure to 30 C. The cooled air has a |
| A. | higher dew point. |
| B. | higher absolute (specific) humidity. |
| C. | higher relative humidity |
| D. | higher wet bulb temperature. |
| Answer» D. higher wet bulb temperature. | |
| 2531. |
Separation of two or more components of a liquid solution can not be achieved by |
| A. | fractional crystallisation |
| B. | liquid extraction |
| C. | absorption |
| D. | evaporation |
| Answer» D. evaporation | |
| 2532. |
Stefan's law describes the mass transfer by |
| A. | diffusion |
| B. | bulk flow |
| C. | both 'a' & 'b' |
| D. | neither 'a' nor 'b' |
| Answer» D. neither 'a' nor 'b' | |
| 2533. |
At minimum reflux ratio for a given separation |
| A. | number of plates is zero. |
| B. | number of plates is infinity. |
| C. | minimum number of the theoretical plates is required. |
| D. | separation is most efficient. |
| Answer» C. minimum number of the theoretical plates is required. | |
| 2534. |
__________ columns are used for liquid dispersion in a continuous gas phase. |
| A. | Packed |
| B. | Pulse |
| C. | Bubble cap |
| D. | Sieve plate |
| Answer» B. Pulse | |
| 2535. |
A globe valve is the most suitable for applications, in which |
| A. | fluid flow control is required. |
| B. | fluid contains dispersed solid particles. |
| C. | valve is required to be either fully open or fully closed. |
| D. | one way flow is required. |
| Answer» B. fluid contains dispersed solid particles. | |
| 2536. |
__________ isused for measuring the static pressure exerted on the wall by a fluid flowing parallel to the wall in a pipeline. |
| A. | Venturimeter |
| B. | Pressure gauge |
| C. | Pitot tube |
| D. | Orificemeter |
| Answer» D. Orificemeter | |
| 2537. |
Pressure drop in packed bed for turbulent flow is given by the __________ equation. |
| A. | Kozney-Karman |
| B. | Blake-Plummer |
| C. | Leva's |
| D. | Hagen-Poiseulle's |
| Answer» C. Leva's | |
| 2538. |
In the complete turbulence zone (in rough pipes), the |
| A. | rough and smooth pipes have the same friction factor. |
| B. | laminar film covers the roughness projections. |
| C. | friction factor depends upon NRe only. |
| D. | friction factor is independent of the relative roughness. |
| Answer» E. | |
| 2539. |
Which of the following has the minimum compressibility ? |
| A. | Water at room temperature |
| B. | Air at room temperature |
| C. | Oxygen at room temperature |
| D. | Nitrogen at room temperature |
| Answer» B. Air at room temperature | |
| 2540. |
Steady fluid flow occurs, when the derivative of flow variables satisfy the following condition. |
| A. | <img src="/_files/images/chemical-engineering/fluid-mechanics/23-322-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/fluid-mechanics/23-322-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/fluid-mechanics/23-322-3.png"> |
| D. | <img src="/_files/images/chemical-engineering/fluid-mechanics/23-322-4.png"> |
| Answer» C. <img src="/_files/images/chemical-engineering/fluid-mechanics/23-322-3.png"> | |
| 2541. |
What is the maximum theoretical suction lift (metres) of a reciprocating pump ? |
| A. | 5 |
| B. | 10 |
| C. | 50 |
| D. | 100 |
| Answer» C. 50 | |
| 2542. |
The terminal velocity of a particle moving through a fluid varies as dpn. The value of n is equal to __________ in Stoke's law regime. |
| A. | 1 |
| B. | 0.5 |
| C. | 2 |
| D. | 1.5 |
| Answer» D. 1.5 | |
| 2543. |
Function of air vessel provided in a reciprocating pump is to |
| A. | reduce discharge fluctuation. |
| B. | reduce the danger of cavitation. |
| C. | avoid the necessity of priming. |
| D. | increase the pump efficiency. |
| Answer» B. reduce the danger of cavitation. | |
| 2544. |
The Prandtl pitot tube measures the |
| A. | velocity at a point in the flow. |
| B. | pressure at a point. |
| C. | average flow velocity. |
| D. | pressure difference in pipe flow. |
| Answer» B. pressure at a point. | |
| 2545. |
Potential function is applicable only for __________ flow. |
| A. | irrotational |
| B. | turbulent |
| C. | steady |
| D. | none of these |
| Answer» B. turbulent | |
| 2546. |
Purpose of relief valve in a reciprocating pump is to |
| A. | protect the pump against developing excessive pressure. |
| B. | facilitate unidirectional flow of liquid. |
| C. | reduce the discharge pressure. |
| D. | control the rate of discharge. |
| Answer» B. facilitate unidirectional flow of liquid. | |
| 2547. |
Select the correct statement. |
| A. | The discharge through a venturimeter depends upon p only and is independent of orientation of the meter. |
| B. | A venturimeter with a given gage difference discharges at a greater rate, when the flow is vertically downward through it, than when the flow is vertically upward. |
| C. | For a given pressure difference, the discharge of gas is greater through a venturimeter, when compressibility is taken into account, than when it is neglected. |
| D. | The overall pressure loss is the same in a given pipe line, whether a venturimeter or a nozzle with the same throat dia is used. |
| Answer» B. A venturimeter with a given gage difference discharges at a greater rate, when the flow is vertically downward through it, than when the flow is vertically upward. | |
| 2548. |
In case of a __________ the energy of flow is considerably decreased downstream of the machine. |
| A. | blower |
| B. | turbine |
| C. | centrifugal pump |
| D. | centrifugal fan |
| Answer» C. centrifugal pump | |
| 2549. |
With increase in the shear rate, the apparent viscosity of pseudoplastic fluids |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | may increase or decrease; depends on the magnitude of shear rate |
| Answer» C. remains same | |
| 2550. |
Purpose of hydraulic accumulator is to |
| A. | ensure intermittant supply of hydraulic pressure. |
| B. | increase the pressure and store/ accumulate it. |
| C. | accumulate pressure to increase force. |
| D. | generate high pressure to operate hydraulic machines like cranes, lifts, presses etc |
| Answer» E. | |