MCQOPTIONS
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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.
| 3701. |
Builders are added in soap to act as |
| A. | cleaning power booster |
| B. | anti-redeposition agent |
| C. | corrosion inhibitor |
| D. | fabric brightener |
| Answer» B. anti-redeposition agent | |
| 3702. |
Fusion of limestone and __________ produces high alumina cement. |
| A. | sand |
| B. | bauxite |
| C. | quicklime |
| D. | calcite |
| Answer» C. quicklime | |
| 3703. |
Massacuits is a terminology used in the __________ industry. |
| A. | paint |
| B. | oil hydrogenation |
| C. | soap |
| D. | sugar |
| Answer» E. | |
| 3704. |
The most economical pulp for the production of newsprint would be the __________ pulp. |
| A. | groundwood |
| B. | sulphate |
| C. | sulphite |
| D. | semichemical |
| Answer» B. sulphate | |
| 3705. |
Prandtl number for most of dry gases is about |
| A. | 0.001 |
| B. | 0.72 |
| C. | 70 |
| D. | 150 |
| Answer» C. 70 | |
| 3706. |
Prandtl number is the reciprocal of |
| A. | Thermal diffusivity/Momentum diffusivity |
| B. | thermal diffusivity x Momentum |
| C. | Thermal diffusivity x Mass diffusivity |
| D. | Mass diffusivity x Momentum diffusivity |
| Answer» B. thermal diffusivity x Momentum | |
| 3707. |
In a heat exchanger with steam outside the tubes, a liquid gets heated to 45 C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be |
| A. | less than 45 C |
| B. | more than 45 C |
| C. | equal to 45 C |
| D. | initially decreases and remains constant thereafter. |
| Answer» C. equal to 45 C | |
| 3708. |
Multiple effect evaporation accounts for |
| A. | steam economy |
| B. | lower operating costs |
| C. | investment economy |
| D. | none of these |
| Answer» B. lower operating costs | |
| 3709. |
In case of a supercooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is |
| A. | more |
| B. | less |
| C. | same |
| D. | more or less; depends on the nature of solution |
| Answer» B. less | |
| 3710. |
Maximum water velocity in tubes of a 1-2 shell and tube heat exchanger may be around __________ metres/second. |
| A. | 1 |
| B. | 10 |
| C. | 20 |
| D. | 30 |
| Answer» B. 10 | |
| 3711. |
Correction is applied to LMTD for __________ flow. |
| A. | parallel |
| B. | counter |
| C. | cross |
| D. | none of these |
| Answer» D. none of these | |
| 3712. |
One kilogram of water at 0 C is changed to superheated steam of one atm pressure and 300 C. The major heat consumption in the process will be to |
| A. | heat the water from 0 C to 100 C. |
| B. | evaporate the water. |
| C. | to superheat the steam. |
| D. | data insufficient, can't be predicted |
| Answer» C. to superheat the steam. | |
| 3713. |
Mode of heat transfer involved in the cooling of air cooled internal combustion engine is |
| A. | conduction |
| B. | natural convection |
| C. | forced convection |
| D. | none of these |
| Answer» C. forced convection | |
| 3714. |
Steady state one dimensional heat flow by conduction as given by Fourier's low does not assume that |
| A. | there is no internal heat generation. |
| B. | boundary surfaces are isothermal. |
| C. | material is anisotropic. |
| D. | constant temperature gradient exists. |
| Answer» D. constant temperature gradient exists. | |
| 3715. |
The left face of a one dimensional slab of thickness 0.2 m is maintained at 80 C and the right face is exposed to air at 30 C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the right face is 10 W/m2.K. At steady state, the temperature of the right face in C is |
| A. | 77.2 |
| B. | 71.2 |
| C. | 63.8 |
| D. | 48.7 |
| Answer» E. | |
| 3716. |
In a shell and tube heat exchanger, the shell side fluid velocity can not be changed by changing the |
| A. | tube layout |
| B. | tube diameter |
| C. | tube pitch |
| D. | no. of baffles |
| Answer» C. tube pitch | |
| 3717. |
To reduce the tube side pressure drop for the same flow rate, the heat exchanger recomended is |
| A. | 1-2 heat exchanger |
| B. | 1-1 heat exchanger |
| C. | 3-2 heat exchanger |
| D. | 2-4 heat exchanger |
| Answer» C. 3-2 heat exchanger | |
| 3718. |
Radiator of an automobile engine is a __________ type of heat exchanger. |
| A. | co-current |
| B. | cross-current |
| C. | counter-current |
| D. | direct contact |
| Answer» E. | |
| 3719. |
In pipe flow, heat is transferred from hot wall to the liquid by |
| A. | conduction only. |
| B. | forced convection only. |
| C. | forced convection and conduction. |
| D. | free and forced convection. |
| Answer» D. free and forced convection. | |
| 3720. |
Multiple effect evaporators ar used to |
| A. | increase the steam economy & decrease the capacity. |
| B. | increase the steam economy & the capacity. |
| C. | decrease the steam economy & the capacity. |
| D. | decrease the steam economy & increase the capacity. |
| Answer» C. decrease the steam economy & the capacity. | |
| 3721. |
Prandtl number is given by |
| A. | <img src="/_files/images/chemical-engineering/heat-transfer/233-16-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/heat-transfer/233-15-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/heat-transfer/233-15-1.png"> |
| D. | <img src="/_files/images/chemical-engineering/heat-transfer/233-16-4.png"> |
| Answer» D. <img src="/_files/images/chemical-engineering/heat-transfer/233-16-4.png"> | |
| 3722. |
Small scale evaporation is done in a |
| A. | heat exchanger |
| B. | condenser |
| C. | multiple effect evaporator |
| D. | steam jacketed kettle |
| Answer» E. | |
| 3723. |
Heat exchanger tubes are never made of |
| A. | plain carbon steel |
| B. | stainless steel |
| C. | lead |
| D. | copper |
| Answer» D. copper | |
| 3724. |
At constant temperature, the thermal conductivities of gases __________ with rise in pressure. |
| A. | decrease |
| B. | increase |
| C. | remain unchanged |
| D. | may increase or decrease; depends on the pressure |
| Answer» B. increase | |
| 3725. |
Reason for operating an evaporator in multiple effect is to secure |
| A. | increased steam economy. |
| B. | decreased steam consumption. |
| C. | both (a) and (b). |
| D. | increased capacity. |
| Answer» D. increased capacity. | |
| 3726. |
In a cooling tower, water becomes cool by |
| A. | loosing sensible heat. |
| B. | heat transfer to surroundings. |
| C. | vaporisation due to heat loss to air. |
| D. | loosing latent heat. |
| Answer» B. heat transfer to surroundings. | |
| 3727. |
In Fourier's law, the proportionality constant is called the |
| A. | heat transfer co-efficient |
| B. | thermal diffusivity |
| C. | thermal conductivity |
| D. | Stefan-Boltzman constant |
| Answer» D. Stefan-Boltzman constant | |
| 3728. |
The heat transfer co-efficient in film type condensation is __________ that for dropwise condensation. |
| A. | greater than |
| B. | lower than |
| C. | is same as |
| D. | half |
| Answer» C. is same as | |
| 3729. |
A __________ evaporator employs an annular downtake. |
| A. | basket type |
| B. | horizontal |
| C. | long tube vertical |
| D. | none of these |
| Answer» B. horizontal | |
| 3730. |
In natural convection heat transfer, the correlating parameter is the |
| A. | Graetz number |
| B. | Eckert number |
| C. | Grashoff number |
| D. | Bond number |
| Answer» D. Bond number | |
| 3731. |
Boiling of milk in an open vessel is an example of __________ boiling. |
| A. | film |
| B. | sub-cooled |
| C. | saturated nucleate |
| D. | none of these |
| Answer» B. sub-cooled | |
| 3732. |
In a heat exchanger, the rate of heat transfer from the hot fluid to the cold fluid |
| A. | varies directly as the area and the LMTD. |
| B. | directly proportional to LMTD and inversely proportional to the area. |
| C. | varies as square of the area. |
| D. | none of these. |
| Answer» B. directly proportional to LMTD and inversely proportional to the area. | |
| 3733. |
With increase in temperature, the total emissivity of conductors |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | decreases linearly |
| Answer» B. decreases | |
| 3734. |
In which mode of heat transfer, the Biot number is important ? |
| A. | Transient heat conduction |
| B. | Natural convection |
| C. | Forced convection |
| D. | Radiation |
| Answer» B. Natural convection | |
| 3735. |
__________ paint has the minimum absorption co-efficient. |
| A. | Black |
| B. | White lead |
| C. | Grey |
| D. | Light cream |
| Answer» C. Grey | |
| 3736. |
Duhring rule is important in solving problems on |
| A. | distillation |
| B. | crystallisation |
| C. | evaporation |
| D. | humidification |
| Answer» D. humidification | |
| 3737. |
Multiple effect evaporation is generally recommended, when the |
| A. | large scale evaporation of liquor is needed. |
| B. | corrosive liquids are to be concentrated. |
| C. | fuel is cheaply available. |
| D. | evaporation on small scale is to be done. |
| Answer» B. corrosive liquids are to be concentrated. | |
| 3738. |
__________ heat exchanger is the most suitable, when the temperature of shell side fluid is much higher than that of tube side. |
| A. | Single pass, fixed tube sheet |
| B. | U-tube |
| C. | Three pass, fixed tube sheet |
| D. | none of these |
| Answer» C. Three pass, fixed tube sheet | |
| 3739. |
For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a __________ evaporator. |
| A. | high pressure |
| B. | vacuum |
| C. | backward feed |
| D. | none of these |
| Answer» C. backward feed | |
| 3740. |
Circulation pump is located below the evaporater to |
| A. | avoid cavitation. |
| B. | avoid frequent priming. |
| C. | create more suction head. |
| D. | none of these. |
| Answer» D. none of these. | |
| 3741. |
The statement that "maximum wavelength of radiation is inversly proportional to the temperature" is __________ law. |
| A. | Stefan-Boltzman's |
| B. | Planck's |
| C. | Wien's displacement |
| D. | none of these |
| Answer» D. none of these | |
| 3742. |
Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low |
| A. | hardness |
| B. | dissolved soilds content |
| C. | suspended solids content |
| D. | all (a), (b) and(c) |
| Answer» E. | |
| 3743. |
At steady state the temperature variation in a plane wall, made of two different solids I & II is shown below :The thermal conductivity of material I |
| A. | is smaller than that of II. |
| B. | is greater than that of II. |
| C. | is equal to that of II. |
| D. | can be greater than or smaller than that of II. |
| Answer» B. is greater than that of II. | |
| 3744. |
Choose the most important factor on which the heat conducted through a wall in a unit time will depend on ? |
| A. | Thickness of the wall. |
| B. | Area of the wall perpendicular to heat flow. |
| C. | Material of the wall. |
| D. | Temperature difference between the two surfaces of the wall. |
| Answer» E. | |
| 3745. |
Which of the following has the minimum thermal conductivity ? |
| A. | Nitrogen |
| B. | Steel |
| C. | Carbon black |
| D. | Tar |
| Answer» B. Steel | |
| 3746. |
Viscosity of gases __________ with increase in temperature. |
| A. | increase very rapidly |
| B. | increase slowly |
| C. | decrease slowly |
| D. | remain unaffected |
| Answer» C. decrease slowly | |
| 3747. |
What is the emissivity of a black body ? |
| A. | 1 |
| B. | 0 |
| C. | 0.90 |
| D. | 0.5 |
| Answer» B. 0 | |
| 3748. |
Steam is routed through the tube in case of a __________ evaporator. |
| A. | basket type |
| B. | horizontal tube |
| C. | short tube vertical |
| D. | long tube vertical |
| Answer» C. short tube vertical | |
| 3749. |
Dropwise condensation of steam on cooling surface is promoted |
| A. | an oily surface. |
| B. | when both the steam and the tube are clean. |
| C. | only in presence of air. |
| D. | none of these. |
| Answer» B. when both the steam and the tube are clean. | |
| 3750. |
Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is |
| A. | 0.1 |
| B. | >1 |
| C. | < 1 |
| D. | l |
| Answer» B. >1 | |