A. Packed towers are preferred for vacuum operation, because the pressure drop through the
packing is less and they (packings) also lessen the possibility of tower wall collapse
B. Packed towers are preferred over plate towers for handling corrosive and foamy liquids
C. Diameter of randomly packed tower is normally more than 1.2 metres
D. Due to uneven supply and improper distribution of liquid, problem of channelling, loading &
flooding is generally encountered in packed towers
Related Mcqs:
- Pick out the wrong statement ?
A. Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure
substance
B. In case of gas absorption, HETP is equal to HTU, when both the operating line & the
equilibrium lines are parallel
C. Hatta number is important in case of gas absorption with chemical reaction
D. In actual practice, absorption is an endothermic process, while stripping is an exothermic
process - Pick out the wrong statement ?
A. In solvent extraction, the distribution co-efficient should be as large as possible for solvent
economy
B. With increase in pressure, the solubility of gases in solvent increases at a fixed temperature
C. Decrease in Murphree plate efficiency is an indication of entrainment in distillation column
D. The capacity of a distillation column is maximum at total reflux - Pick out the wrong statement ?
A. Change in barometric pressure does not affect the relative humidity
B. In case of a packed tower, the operating velocity is about half of the flooding velocity,
generally
C. ‘Elution’ means the desorption of the adsorbed solute by a solvent
D. The equilibrium moisture content of the solid can be reduced by increasing the absolute
humidity - Pick out the wrong statement pertaining to the cooling towers ?
A. In case of induced draft cooling tower, the fan is placed at the top of the tower
B. Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and
hot discharged air
C. A natural draft cooling tower is recommended to be used, when the air humidity is low and air
temperature is also low
D. Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb
temperature - Pick out the wrong statement?
A. The binary diffusivity in liquids is of the order of 10-5 cm2/sec
B. Molecular diffusion in solid is much faster than that in liquids
C. Particles movement from higher concentration to lower concentration takes place in diffusion
process
D. According to Poiseuille’s law, the permeability decreases with increase in temperature for
flow of a gas through a given capillary - Pick out the wrong statement?
A. Change in barometric pressure does not affect the relative humidity
B. In case of a packed tower, the operating velocity is about half of the flooding velocity,
generally
C. ‘Elution’ means the desorption of the adsorbed solute by a solvent
D. The equilibrium moisture content of the solid can be reduced by increasing the absolute
humidity - Pick out the wrong statement?
A. The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same
for NSc = NPr= 1
B. 1 Nm3 of dry air is lighter than 1Nm3 of humid air
C. The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass
diffusivity
D. An Azeotropic mixture of two liquids has boiling point higher than either of them, when it
shows negative deviation from Raoult’s Law - Pick out the wrong statement ?
A. Constant pressure distillation cannot separate an Azeotropic mixture
B. Relative volatility of a binary mixture changes appreciably with the minor change in
temperature
C. The relative volatility of a binary mixture at Azeotropic composition is unity
D. Flash distillation is practised on wide spread scale in petroleum refinery - Pick out the wrong statement ?
A. Cellulose acetate membranes are used in dialysis process
B. Elutriation process refers to when the soluble material is largely concentrated on the surface of
an insoluble solid and is simply washed off by the solvent
C. ‘Cascade’ means a group of stages interconnected so that various streams flow from one to
another
D. Zirconia probe is used for the humidity measurement - Pick out the wrong statement?
A. The operating line always lies above the equilibrium solubility curve in case of a single
component absorber
B. The operating line always lies below the equilibrium solubility curve in case of a single
component stripper
C. The operating pressure in solvent extraction system should be below vapor pressures of all
components
D. The solubility of a particular gas in ideal solution in any solvent is always the same
