MCQOPTIONS
Saved Bookmarks
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.
| 3651. |
Saponification value/number of an oil or fat is a measure of its |
| A. | fatty acid content. |
| B. | degree of unsaturation of the fatty acids present in it. |
| C. | average molecular weight. |
| D. | insoluble fatty acid content. |
| Answer» D. insoluble fatty acid content. | |
| 3652. |
Ethyl alcohol cannot be produced |
| A. | from waste sulphite substrate of paper mills. |
| B. | by esterification and hydroloysis of ethylene. |
| C. | from molasses. |
| D. | none of these. |
| Answer» E. | |
| 3653. |
Low thermal conductivity of heat insulating materials is due to its |
| A. | dense structure. |
| B. | high proportion of air space. |
| C. | high specific heat. |
| D. | none of these. |
| Answer» C. high specific heat. | |
| 3654. |
The most conducive surface for dropwise condensation to occur is the __________ surface. |
| A. | coated |
| B. | oily |
| C. | glazed & polished |
| D. | smooth |
| Answer» C. glazed & polished | |
| 3655. |
In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is equality of |
| A. | concentrations |
| B. | chemical potentials |
| C. | activity co-efficients |
| D. | mass transfer co-efficients |
| Answer» B. chemical potentials | |
| 3656. |
Calburn analogy is applicable for the value of Prandtl number from |
| A. | 0.001 to 1 |
| B. | 0.6 to 120 |
| C. | 0.5 to 5 |
| D. | 120 to 400 |
| Answer» C. 0.5 to 5 | |
| 3657. |
For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of |
| A. | 1 |
| B. | 1.74 |
| C. | 6.1 |
| D. | 37 |
| Answer» D. 37 | |
| 3658. |
The inner wall of a furnace is at a temperature of 700 C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1. C-1 respectively. The ambient air is at 30 C and the heat transfer co-efficient between the outer surface of wall and air is 20 W.m-2. C-1. The rate of heat loss from the outer surface in W.m-2is |
| A. | 165.4 |
| B. | 167.5 |
| C. | 172.5 |
| D. | 175 |
| Answer» B. 167.5 | |
| 3659. |
Value of Nusselt number [Nu = (hD/k)] for the heat transfer by conduction from a droplet or a spherical particle to a surrounding stagnant film is |
| A. | 0.5 |
| B. | 2 |
| C. | 10 |
| D. | 100 |
| Answer» C. 10 | |
| 3660. |
Sensible heat of hot industrial flue gases can not be recovered by a/an |
| A. | economiser |
| B. | regenerator |
| C. | ceramic recuperator |
| D. | none of these |
| Answer» E. | |
| 3661. |
Which of the following has the minimum absorptivity ? |
| A. | Aluminium foil |
| B. | Coal dust |
| C. | Refractory bricks |
| D. | Iron plates |
| Answer» B. Coal dust | |
| 3662. |
A black body when hot, emits heat radiation of __________ wavelengths. |
| A. | small |
| B. | large |
| C. | all |
| D. | one fixed |
| Answer» D. one fixed | |
| 3663. |
Vibrations in the tubes of a shell and tube heat exchanger is induced due to the |
| A. | flow of fluid on the tube and shell sides. |
| B. | oscillations in the flow of shell/tube sides fluid. |
| C. | vibrations transmitted through piping and/or supports due to external reasons. |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 3664. |
Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is |
| A. | 0.2 |
| B. | 0.4 |
| C. | 0.6 |
| D. | 0.8 |
| Answer» D. 0.8 | |
| 3665. |
In a gas-liquid shell and tube heat exchanger, the |
| A. | presence of a non-condensible gas decreases the condensing film co-efficient. |
| B. | gases under high pressure are routed through the tube side, because high pressure gases are corrosive in nature. |
| C. | gases to be heated/cooled is normally routed through the shell side, because the corrosion caused by the cooling water or steam condensate remain localised to the tubes. |
| D. | all 'a', 'b' & 'c' |
| Answer» E. | |
| 3666. |
Which is the most suitable for the concentration of foamy & frothy liquors ? |
| A. | Agitated film evaporator |
| B. | Long tube vertical evaporator |
| C. | Open pan evaporator |
| D. | None of these |
| Answer» C. Open pan evaporator | |
| 3667. |
Boiling point elevation of an ideal solution |
| A. | increases rapidly with temperature rise. |
| B. | decreases rapidly with temperature rise |
| C. | in independent of pressure. |
| D. | both (b) and (c). |
| Answer» B. decreases rapidly with temperature rise | |
| 3668. |
The rate of heat transfer is a product of overall heat transfer co-efficient, the difference in temperature and the |
| A. | heating volume |
| B. | heat transfer area |
| C. | Nusselt number |
| D. | none of these |
| Answer» C. Nusselt number | |
| 3669. |
Which of the following has the lowest overall heat transfer co-efficient ? |
| A. | Dowtherm |
| B. | Molten sodium |
| C. | Water |
| D. | Air |
| Answer» E. | |
| 3670. |
For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone. |
| A. | extremely low |
| B. | low |
| C. | high |
| D. | no |
| Answer» D. no | |
| 3671. |
Heat exchangers operating, when the asymptotic range is reached, |
| A. | provide very large heat transfer co-efficient. |
| B. | results in making part of the heating surface inactive. |
| C. | results in abruptly increased velocity. |
| D. | none of these. |
| Answer» C. results in abruptly increased velocity. | |
| 3672. |
In case of heat transfer by conduction in a hollow cylinder, __________ mean area is used to calculate the heat transfer rate. |
| A. | geometric |
| B. | arithmetic |
| C. | logarithmic |
| D. | either (a), (b) or (c) |
| Answer» D. either (a), (b) or (c) | |
| 3673. |
Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by This is valid for the value of NRe equal to |
| A. | < 2100 |
| B. | 2100-4000 |
| C. | > 4000 |
| D. | > 10000 |
| Answer» E. | |
| 3674. |
Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m2 C. |
| A. | 10-50 |
| B. | 100-500 |
| C. | 1000-1500 |
| D. | 5000-15000 |
| Answer» E. | |
| 3675. |
Evaporation by thermocompression results in the |
| A. | saving of steam. |
| B. | realisation of multiple effect economy in a single effect. |
| C. | both (a) and (b). |
| D. | none of these. |
| Answer» D. none of these. | |
| 3676. |
Forced circulation evaporators are normally used for concentrating liquids having |
| A. | scaling characteristics |
| B. | high viscosity |
| C. | both(a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 3677. |
Steam economy in case of a triple effect evaporator will be |
| A. | 1 |
| B. | < 1 |
| C. | > 1 |
| D. | between 0 and 1 |
| Answer» D. between 0 and 1 | |
| 3678. |
The purpose of providing expansion bellows in the shell of tubular exchanger is to |
| A. | increase the heating load. |
| B. | impart structural strength. |
| C. | account for the uneven expansion of shell and tube bundles. |
| D. | facilitate increase of shell length, if needed. |
| Answer» D. facilitate increase of shell length, if needed. | |
| 3679. |
A graph between __________ is called Wilson plot. |
| A. | <img src="/_files/images/chemical-engineering/heat-transfer/251-256-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/heat-transfer/251-256-2.png"> |
| C. | <i>v<sup>0.8</sup> Vs . U</i> |
| D. | <img src="/_files/images/chemical-engineering/heat-transfer/251-256-4.png"> |
| Answer» B. <img src="/_files/images/chemical-engineering/heat-transfer/251-256-2.png"> | |
| 3680. |
In a laboratory test run, the rate of drying was found to be 0.5 x 10-3 kg/m2.s, when the moisture content reduced from 0.4 to 0.1 on dry basis. The critical moisture content of the material is 0.08 on a dry basis. A tray dryer is used to dry 100 kg (dry basis) of the same material under identical conditions. The surface area of the material is 0.04 m2/kg of dry solid. The time required (in seconds) to reduce the moisture content of the solids from 0.3 to 0.2 (dry basis) is |
| A. | 2000 |
| B. | 4000 |
| C. | 5000 |
| D. | 6000 |
| Answer» D. 6000 | |
| 3681. |
In Biot number, the characteristic length used is the ratio of the __________ of the solid. |
| A. | volume to surface area |
| B. | perimeter to surface area |
| C. | surface area to volume |
| D. | surface area to perimeter |
| Answer» B. perimeter to surface area | |
| 3682. |
Which of the following is the most widely used heat insulating material for pipelines carrying steam ? |
| A. | Tar dolomite bricks followed by asbestos. |
| B. | Fireclay refractory followed by aluminium sheet. |
| C. | Cotton followed by aluminium foil. |
| D. | 85% magnesia cement and glass wool. |
| Answer» E. | |
| 3683. |
Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re0.8 . Prn, is not valid, if the value of |
| A. | n = 0.4 is used for heating. |
| B. | n = 0.3 is used for cooling. |
| C. | Reynolds number for the flow involved is > 10000. |
| D. | Reynolds number for the flow involved is < 2100. |
| Answer» E. | |
| 3684. |
Which is the best tube arrangement (in a shell and tube heat exchanger) if the fluids are clean and non-fouling ? |
| A. | Square pitch |
| B. | Triangular pitch |
| C. | Diagonal square pitch |
| D. | None of these |
| Answer» C. Diagonal square pitch | |
| 3685. |
In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid |
| A. | is inversely proportional to the resistance across which the drop occurs. |
| B. | and the wall are proportional to individual resistances. |
| C. | and the wall is not related. |
| D. | none of these. |
| Answer» C. and the wall is not related. | |
| 3686. |
'Duhring's plot' is of use in |
| A. | extractive distillation |
| B. | evaporation |
| C. | leaching |
| D. | absorption |
| Answer» C. leaching | |
| 3687. |
Which has the lowest Prandtl number ? |
| A. | Liquid metal |
| B. | Aqueous solution |
| C. | Water |
| D. | Lube oil |
| Answer» B. Aqueous solution | |
| 3688. |
__________ are used as corrosion inhibitor for iron & steel in aqueous solutions. |
| A. | Phosphates |
| B. | Chromates |
| C. | Sulphates |
| D. | Bi-carbonates |
| Answer» C. Sulphates | |
| 3689. |
L.D. converter is used in the production of |
| A. | pig iron |
| B. | steel |
| C. | copper |
| D. | zinc |
| Answer» C. copper | |
| 3690. |
The terminology 'BTX' used in coal tar distillation industry refers to |
| A. | benzol-toluol-xylol. |
| B. | benzol-toluene-xylene. |
| C. | benzene-toluol-xylol. |
| D. | benzene-toluene-xylene. |
| Answer» E. | |
| 3691. |
Ceramics are produced from silicates or clayish materials: Which of the following is not a ceramic material ? |
| A. | Slag cement |
| B. | Glasses |
| C. | Porcelain/Potteries |
| D. | Teflon |
| Answer» E. | |
| 3692. |
Glass is |
| A. | mainly CaO |
| B. | subjected to galvanising |
| C. | a super cooled liquid |
| D. | all (a), (b) and (c) |
| Answer» D. all (a), (b) and (c) | |
| 3693. |
Analgesic drugs are |
| A. | pain relievers |
| B. | antibiotics |
| C. | used in the treatment of T.B. |
| D. | used in the treatment of typhiod |
| Answer» B. antibiotics | |
| 3694. |
Purity of oxygen used for blowing in steel making L.D. converter is 99.5%. The boiling point of oxygen is about __________ C. |
| A. | -53 |
| B. | -103 |
| C. | -183 |
| D. | -196 |
| Answer» D. -196 | |
| 3695. |
Commonly used glass is known as the __________ glass. |
| A. | flint |
| B. | hard |
| C. | pyrex |
| D. | soda |
| Answer» E. | |
| 3696. |
Zeolite is a/an |
| A. | naturally occuring clay which is capable of exchanging cations. |
| B. | abrasive material. |
| C. | catalyst used in shift conversion. |
| D. | none of these. |
| Answer» B. abrasive material. | |
| 3697. |
Type of glass used in optical work is the __________ glass. |
| A. | soda-lime |
| B. | fibre |
| C. | lead |
| D. | borosilicate |
| Answer» D. borosilicate | |
| 3698. |
Pick out the wrong statement pertaining to the soap manufacture. |
| A. | Transparent soaps are made by cold process. |
| B. | Organic pigments are used as colouring materials in the soap manufacture. |
| C. | Both laundary as well as toilet soaps are manufactured by hot process. |
| D. | Colourless rosin is used in the manufacture of laundary soaps. |
| Answer» B. Organic pigments are used as colouring materials in the soap manufacture. | |
| 3699. |
Essential oils are usually obtained using |
| A. | steam distillation |
| B. | extractive distillation |
| C. | solvent extraction |
| D. | leaching |
| Answer» E. | |
| 3700. |
Hydrogenation of oil/fat does not |
| A. | improve its resistance to rancid oxidation. |
| B. | raise its melting point. |
| C. | remove double bonds. |
| D. | none of these. |
| Answer» E. | |