Chemical Engineering :: All Aptitude Test ::

1.Co-current absorbers are usually used when the gas to be dissolved in the liquid is _____?
A. Sparingly soluble
B. Highly soluble
C. A pure substance
D. Sparingly soluble

2.In triangular co-ordinates, the ternary composition point falls ____ of the triangle?
A. In the corners
B. Inside
C. On the sides
D. In the corners

3.The velocity, concentration and temperature boundary, for the boundary layer development on a flat plate during connective mass transfer will be same, if__?
A. NSc = 1
B. NSc = NPr = NLe
C. NPr = NLe
D. NSc = 1

4.During sensible cooling process ___?
A. Relative humidity decreases
B. Relative humidity increases
C. Wet bulb temperature decreases
D. Relative humidity decreases

5.The boiling points of pure components of a binary system __________ with increase in total pressure of the system ?
A. Decreases
B. Increases
C. Remains unchanged
D. Decreases

6.Large scale usage of flash distillation is practised in ___?
A. Soap manufacturing
B. Ammonia synthesis plant
C. Polymerisation industry
D. Soap manufacturing

7.To remove all the moisture from a wet solid it requires exposure to ____ air?
A. Perfectly dry
B. Highly humid
C. High temperature
D. Perfectly dry

8.The cooling effect in a cooling tower can be speeded up by ____?
A. Increasing the air velocity and area of exposed wet surface
B. Reducing the barometric pressure
C. Reducing the humidity of the air
D. Increasing the air velocity and area of exposed wet surface

9.The Knudsen diffusivity is proportional to (where, T = absolute temperature)?
A. ?T
B. T2
C. T
D. ?T

10.A natural draft cooling tower is filled with wooden grids, which covers about ____ percent of the tower height?
A. 15-Oct
B. 30-40
C. 70-80
D. 15-Oct

11.With increase in the liquid flow rate at a fixed gas velocity in a randomly packed counter current gas-liquid absorption column, the gas pressure drop___?
A. Decreases
B. Remains unchanged
C. Increases
D. Decreases

12.For the flow of gases through a capillary, with increase in temperature, the permeability ______ as per Knudsen law?
A. Increases
B. Decreases
C. Remain same
D. Increases

13.Moisture content of a substance when at equilibrium with a given partial pressure of the vapour is called the _______ moisture?
A. Free
B. Unbound
C. Equilibrium
D. Free

14.For absorbing a sparingly soluble gas in a liquid, the___?
A. Gas side co-efficient should be increased
B. Liquid side coefficient should be increased
C. Gas side co-efficient should be decreased
D. Gas side co-efficient should be increased

15.The relative volatility of a binary mixture at the Azeotropic composition is?
A. 1-Jan
B. > 1
C. 0
D. 1-Jan

16.Penetration theory states that the mass transfer co-coefficient is equal to (where, De is diffusivity and �t� is time) ?
A. (De.t)1/2
B. (De/t)1/2
C. (4De/?t)1/2
D. (De.t)1/2

17.The equation, NA = (DAB . Pt /RTZ) (y1 � y2) is for ____?
A. Steady state equimolar counter diffusion
B. Fick�s first law of diffusion
C. Steady state diffusion for stagnant case
D. Steady state equimolar counter diffusion

18.Coffee is prepared from coffee beans by leaching with___?
A. Cold water
B. Hot water
C. Dilute hot caustic solution
D. Cold water

19.Which of the following parameters remains constant during chemical dehumidification ?
A. Dry bulb temperature
B. Partial pressure of vapour
C. Wet bulb temperature
D. Dry bulb temperature

20.A slurry is to be dried to produce flaky solid. Which dryer would you recommend ?
A. Spray dryer
B. Drum dryer
C. Rotary dryer
D. Spray dryer

21.In steam distillation, the __?
A. Temperature is 100�C
B. Temperature is more than 100� C
C. Product must be immiscible with water
D. Temperature is 100�C

22.Dried finished product sampled from various parts of a ____ dryer exhibits nonuniformity in the moisture content?
A. Rotary
B. Tray
C. Freeze
D. Rotary

23.The value of �L/mG� ratio for economical absorption operation ranges from?
A. 0.5 to 0.8
B. 0.8 to 1.2
C. 1.25 to 2.0
D. 0.5 to 0.8

24.Large quantity of silica gel is normally dried in a __ dryer?
A. Freeze
B. Through circulation
C. Rotary vacuum
D. Freeze

25.Mass transfer co-efficient is defined as__?
A. Flux = Co-efficient/concentration difference
B. Co-efficient = Flux/concentration difference
C. Flux=concentration difference/coefficient
D. Flux = Co-efficient/concentration difference

26.Unsaturated air (with dry and wet bulb temperatures being 35 and 25�C respectively) is passed through water spray chamber maintained at 35�C. The air will be___?
A. Cooled
B. Humidified
C. Dehumidified
D. Cooled

27.In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the ___ number ?
A. Lewis
B. Grashoff
C. Sherwood
D. Lewis

28.In an absorption column, the flooding velocity for random packing is ____ that for stacked/regular packing?
A. Greater than
B. Smaller than
C. Equal to
D. Greater than

29.In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed___?
A. q > 1
B. q < 1
C. q = 1
D. q > 1

30.With increase in temperature, the leaching rate increases due to___?
A. Decreased liquid viscosity
B. Increased diffusivity
C. Both A. and B.
D. Decreased liquid viscosity


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