Unit Operations

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following does the terminal velocity of a particle NOT depend on?
Density of fluid and particle
Shape of the particle
Viscosity of the fluid
None of the mentioned
Explanation:
The terminal velocity of a particle depends on all the mentioned factors.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Basket centrifuge can be used for liquid-liquid separations.
True
False
Explanation:
Basket centrifuge cannot be used for liquid-liquid separations.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: Horizontal tube evaporator is easy for cleaning.
True, False
True, True
False, False
False, True
Explanation:
Horizontal tube evaporator is easy for cleaning as the evaporator part can be easily dismantled from the rest of the equipment parts. Horizontal tube evaporator has a disadvantage of hindering agitation of the feed as it is present outside the horizontal tubes.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: Vibro-fluidized bed dryer can reduce the air flow rate consumptions as air is only used for drying and not for fluidizing.
True, screw conveyor
True, pneumatic conveyor
False, screw conveyor
False, pneumatic conveyor
Explanation:
Vibro-fluidized bed dryer can reduce the air flow rate consumptions as air is only used for drying and not for fluidizing. Mechanical vibratory motion is used for fluidization. Screw conveyors are often called desolventizers because the main purpose is to remove the solvent from the pastes and not to recover it.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
What does excess supersaturating followed by cooling lead to?
Primary nucleation
Secondary nucleation
Both, nucleation and crystal growth in general
None of the mentioned
Explanation:
Excess supersaturating followed by cooling only leads to primary nucleation. That’s like the formation of only the first crystal. Secondary nucleation is due to the agglomeration of crystals which is desirable.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is the cheapest filtration equipment?
Plate and frame filter press
Pressure leaf filter press
Continuous Rotary Vacuum Filter Press
None of the mentioned
Explanation:
Plate and frame filter press is the cheapest filtration equipment among all the equipment.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
When there is a mixture of liquids present, the boiling point lies between the boiling points of both the components.
True
False
Explanation:
When there is a mixture of liquids present, the boiling point lies between the boiling points of both the components.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: Where Pg is power for a gassed system and Po is power for an ungassed system, Pg/Po is _____
< 1, aeration number
> 1, aeration number
< 1, consistency index
> 1, consistency index
Explanation:
Power required for an ungassed system Po is more than that required for a gassed system Pg. This is because when gas is sent into the fluid via a nozzle, the density of the fluid near the impeller decreases and hence the power required for it is lesser.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Drain pipes are present to remove _____
Waste
Urea
Condensate
None of the mentioned
Explanation:
Drain pipes are present to remove Condensate.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
With respect to the Tyler series, which of the following is true?
The ratio of one mess size to the intermediate mesh will have the ratio of 4th root of 2
Intermediate messes cannot be accommodated in the Tyler series
Intermediate meshes can be accommodated in British series only
None of the mentioned
Explanation:
Intermediate meshes can be accommodated in Tyler series and the ratio of one mess size to the intermediate mesh will have the ratio of 4th root of 2