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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.
| 3801. |
Asymptotic conditions is reached, when for a fluid flowing in laminar flow through a long tube |
| A. | exit-fluid temperature > wall temperature. |
| B. | exit fluid temperature < wall temperature. |
| C. | exit fluid temperature = wall temperature. |
| D. | Graetz number > 100. |
| Answer» D. Graetz number > 100. | |
| 3802. |
1000 kg of wet solids are to be dried from 60% to 20% moisture (by weight). The mass of moisture removed in kg is |
| A. | 520 |
| B. | 200 |
| C. | 400 |
| D. | 500 |
| Answer» D. 500 | |
| 3803. |
Which is the most suitable for the con-certration of highly concentrated solution? |
| A. | Open pan evaporation |
| B. | Long tube vertical evaporator |
| C. | Agitated film evaporator |
| D. | None of these |
| Answer» B. Long tube vertical evaporator | |
| 3804. |
Loss of heat from untagged steam pipe to the ambient air is by |
| A. | conduction |
| B. | convection |
| C. | radiation |
| D. | all (a), (b) & (c) |
| Answer» E. | |
| 3805. |
Fruit juice (a heat sensitive material) can be concentrated in a __________ evaporator. |
| A. | long tube |
| B. | falling film |
| C. | high pressure |
| D. | none of these |
| Answer» C. high pressure | |
| 3806. |
Tubes are held between top and bottom tube sheets in Calenderia type evaporator by keeping |
| A. | both the tube sheets fixed. |
| B. | both the tube sheets floating. |
| C. | the top tube sheet floating and bottom tube sheet fixed. |
| D. | the top tube sheet fixed and the bottom tube-sheet floating. |
| Answer» B. both the tube sheets floating. | |
| 3807. |
The type of liquor circulation system to be ' employed in evaporators (viz. natural or forced circulation) is determined mainly by the __________ of the liquid. |
| A. | viscosity |
| B. | density |
| C. | thermal conductivity |
| D. | corrosive nature |
| Answer» B. density | |
| 3808. |
Thermal diffusivity is the most important in heat transfer by |
| A. | conduction |
| B. | radiation |
| C. | condensation |
| D. | natural convection |
| Answer» B. radiation | |
| 3809. |
(NGr x NPr) is called the __________ number. |
| A. | Graetz |
| B. | Reyleigh |
| C. | Nusselt |
| D. | Stanton |
| Answer» C. Nusselt | |
| 3810. |
A dephlegmator is a |
| A. | total condenser |
| B. | vacuum evaporator |
| C. | partial condenser |
| D. | double pipe heat exchanger |
| Answer» D. double pipe heat exchanger | |
| 3811. |
Intermittant tube cleaning is possible to be done in case of a __________ evaporator. |
| A. | basket type |
| B. | horizontal tube |
| C. | calendria |
| D. | none of these |
| Answer» B. horizontal tube | |
| 3812. |
Harmonic mean temperature difference is given by |
| A. | <span class="root"><i> T<sub>1</sub> </i>. <i> T<sub>2</sub></i></span> |
| B. | <img src="/_files/images/chemical-engineering/heat-transfer/259-370-1.png"> |
| C. | <img src="/_files/images/chemical-engineering/heat-transfer/259-370-2.png"> |
| D. | <img src="/_files/images/chemical-engineering/heat-transfer/259-370-3.png"> |
| Answer» C. <img src="/_files/images/chemical-engineering/heat-transfer/259-370-2.png"> | |
| 3813. |
Three solid objects of the same material and of equal mass-a sphere, a cylinder (length = diameter) and a cube are at 500 C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change in temperature is the smallest for |
| A. | cube |
| B. | cylinder |
| C. | sphere |
| D. | equal for all the three |
| Answer» B. cylinder | |
| 3814. |
The main component of pyrex glass is |
| A. | zinc |
| B. | lead |
| C. | boron |
| D. | celenium |
| Answer» C. boron | |
| 3815. |
Alum [Al2(SO4)3] is used as a coagulant in water treatment to remove |
| A. | colour |
| B. | turbidity |
| C. | bacteria |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 3816. |
__________ is an ore concentrating metallurgical process involving a chemical change. |
| A. | Electromagnetic separation |
| B. | Froth floatation |
| C. | Roasting |
| D. | none of these |
| Answer» D. none of these | |
| 3817. |
Basic oxide is absent in __________ glass. |
| A. | flint |
| B. | pyrex |
| C. | quartz |
| D. | all (a), (b) & (c) |
| Answer» D. all (a), (b) & (c) | |
| 3818. |
Graphite is a/an |
| A. | electrical insulator. |
| B. | allotrope of carbon. |
| C. | moderator used in nuclear reactor. |
| D. | both (b) and (c). |
| Answer» E. | |
| 3819. |
90% of the caprolactum is converted to nylon-6 on its condensation polymerisation in the reactor maintained at __________ C. |
| A. | <0 |
| B. | 10-30 |
| C. | 250-280 |
| D. | 500-600 |
| Answer» C. 250-280 | |
| 3820. |
Vegetable oils contain large quantity of glycerides of unsaturated acids. When the vegetable oils contain high amount of saturated fatty acids, it is termed as __________ oil. |
| A. | drying |
| B. | semi-drying |
| C. | non-drying |
| D. | none of these |
| Answer» D. none of these | |
| 3821. |
Fats as compared to oils have |
| A. | more unsaturated glycerides of fatty acids. |
| B. | less unsaturated glycerides of fatty acids. |
| C. | much higher reactivity to oxygen. |
| D. | lower melting point. |
| Answer» C. much higher reactivity to oxygen. | |
| 3822. |
Thermal pyrolysis of ethylene dichloride produces |
| A. | trichloroethylene |
| B. | vinyl chloride |
| C. | ethanol amine |
| D. | ethylene oxide |
| Answer» C. ethanol amine | |
| 3823. |
Fermentator temperature during production of alcohol from molasses is around __________ C. |
| A. | 5 |
| B. | 30 |
| C. | 150 |
| D. | 300 |
| Answer» C. 150 | |
| 3824. |
Which of the following coals has the highest calorific value ? |
| A. | Lignite |
| B. | Sub-bituminous |
| C. | Anthracite |
| D. | Peat |
| Answer» D. Peat | |
| 3825. |
Which of the following is not an abrasive material ? |
| A. | Bakelite |
| B. | Pumice |
| C. | Corundum |
| D. | Carborundum |
| Answer» B. Pumice | |
| 3826. |
Finely ground calcium aluminate & silicate is a/an |
| A. | cermet |
| B. | cement |
| C. | abrasive |
| D. | explosive |
| Answer» C. abrasive | |
| 3827. |
For the hydrogenation of oils __________ (A) __________ is commonly used as catalyst and __________ (B) __________ is a catalyst poison. |
| A. | (A) platinum (B) sulphur |
| B. | (A) palladium (B) oxygen |
| C. | (A) nickel (B) sulphur |
| D. | (A) nickel (B) oxygen |
| Answer» D. (A) nickel (B) oxygen | |
| 3828. |
Main constituents of natural rubber is |
| A. | polystyrene |
| B. | polyisoprene |
| C. | polybutadiene |
| D. | polychloroprene |
| Answer» C. polybutadiene | |
| 3829. |
Highly porous refractory bricks are |
| A. | less susceptible to chemical attack by molten fluxes and gases etc. |
| B. | very strong. |
| C. | having very high thermal conductivity. |
| D. | none of these. |
| Answer» E. | |
| 3830. |
Fumigant insecticides |
| A. | kill insects, when they eat it. |
| B. | emit poisonous vapour. |
| C. | are absorbed throughout the plant. |
| D. | none of these. |
| Answer» C. are absorbed throughout the plant. | |
| 3831. |
Polyvinyl chloride (PVC) is |
| A. | a thermosetting material. |
| B. | a condensation polymerisation product. |
| C. | made by employing emulsion polymerisation. |
| D. | none of these. |
| Answer» D. none of these. | |
| 3832. |
Bleaching of paper pulp is done with |
| A. | activated clay |
| B. | bromine |
| C. | chlorine or chlorine dioxide |
| D. | magnesium sulphite |
| Answer» D. magnesium sulphite | |
| 3833. |
Isopropyl benzene produced by alkylation of benzene with propylene is known as |
| A. | neoprene |
| B. | cumene |
| C. | gelatin |
| D. | mercaptans |
| Answer» C. gelatin | |
| 3834. |
Exothermic neutralisation reaction between caustic soda and dodecylbenzene sulphonic acid produces sodium dodecylbenzene sulphate, which is a/an |
| A. | explosive |
| B. | soap |
| C. | detergent |
| D. | analgesic drug |
| Answer» D. analgesic drug | |
| 3835. |
Conversion of SO2 to SO3 in Monsanto 4-pass converter is about __________ percent. |
| A. | 80 |
| B. | 90 |
| C. | 98 |
| D. | 100 |
| Answer» D. 100 | |
| 3836. |
Chemical name of 'alum' is |
| A. | barium sulphate. |
| B. | aluminium sulphate. |
| C. | aluminium chloride. |
| D. | calcium sulphate. |
| Answer» C. aluminium chloride. | |
| 3837. |
A bio-catalyst produced by living cells which acts independent of the cell is called a/an |
| A. | substrate |
| B. | enzyme |
| C. | nutrient |
| D. | none of these |
| Answer» C. nutrient | |
| 3838. |
Nusselt number is the ratio of the temperature gradient at the wall to |
| A. | temperature difference |
| B. | heat flux |
| C. | that across the entire pipe |
| D. | none of these |
| Answer» D. none of these | |
| 3839. |
The Stefan-Boltzman constant depends on the |
| A. | medium |
| B. | temperature |
| C. | surface |
| D. | none of these |
| Answer» E. | |
| 3840. |
Thermal conductivity of a gas at low density, __________ with increase in temperature. |
| A. | decreases |
| B. | increases |
| C. | remains unchanged |
| D. | may increase or decrease; depends on the gas |
| Answer» C. remains unchanged | |
| 3841. |
Nusselt number is a function of Prandtl number and __________ number of fluid in natural convection heat transfer. |
| A. | Grashoff |
| B. | Biot |
| C. | Stantan |
| D. | Reynolds |
| Answer» B. Biot | |
| 3842. |
Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. |
| A. | Grashoff |
| B. | Reynolds |
| C. | both 'a' & 'b' |
| D. | Prandtl & Grashoff |
| Answer» E. | |
| 3843. |
The thermal boundary layer at NPr > 1 |
| A. | is thicker than hydrodynamic boundary layer. |
| B. | is thinner than hydrodynamic boundary layer. |
| C. | and the hydrodynamic boundary layer are identical. |
| D. | disappears. |
| Answer» C. and the hydrodynamic boundary layer are identical. | |
| 3844. |
With increase in temperature, the thermal conductivity of fresh lubricating oil |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | may increase or decrease; depends on its composition |
| Answer» C. remains unchanged | |
| 3845. |
Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. The kg of water removed from 1 kg fresh juice is |
| A. | 0.4 |
| B. | 0.5 |
| C. | 0.6 |
| D. | 0.7 |
| Answer» E. | |
| 3846. |
The unit of conductance in SI unit is |
| A. | W/m |
| B. | W/m |
| C. | <sup>2</sup> |
| D. | W/ K |
| E. | W/m K |
| Answer» D. W/ K | |
| 3847. |
In a shell and tube heat exchanger, square pitch compared to triangular pitch |
| A. | gives a higher shell side pressure drop. |
| B. | gives a lower shell side pressure drop. |
| C. | can pack more surface area into a shell of given diameter. |
| D. | none of these. |
| Answer» C. can pack more surface area into a shell of given diameter. | |
| 3848. |
Which of the following has maximum thermal conductivity ? |
| A. | Iron |
| B. | Coal |
| C. | Nitrogen |
| D. | Tar |
| Answer» B. Coal | |
| 3849. |
A wall has two layers of materials A and B; each made of a different material. Both the layers have the same thickness. The thermal conductivity of materialA is twice that of B. Under the equilibrium, the temperature difference across the wall is 36 C. The temperature difference across the layer A is __________ C. |
| A. | 6 |
| B. | 12 |
| C. | 18 |
| D. | 24 |
| Answer» C. 18 | |
| 3850. |
The film co-efficient between condensing vapour and metal wall increases with |
| A. | increasing temperature of the vapour. |
| B. | decreasing temperature of the vapour. |
| C. | increasing viscosity of the film of condensate. |
| D. | increasing temperature drop. |
| Answer» B. decreasing temperature of the vapour. | |