8247 + Mcqs in Chemical Engineering Page 57 McqOptions

2801.	A fluid whose apparent viscosity increases with shear rate is termed as the __________ fluid.
A.	Newtonion
B.	viscous
C.	dilatant
D.	non-viscous
Answer» D. non-viscous

Discussion

2802.	Out of the following flow measuring devices, which one incurs the maximum installation cost as well as pressure loss ?
A.	Flow nozzle
B.	Venturimeter
C.	Rotameter
D.	Orificemeter
Answer» C. Rotameter

Discussion

2803.	Which of the following has the maximum compression ratio ?
A.	Blower
B.	Compressor
C.	Vacuum pump
D.	Fan
Answer» D. Fan

Discussion

2804.	Scale up of agitator design requires
A.	geometrical similarity only.
B.	dynamic similarity only.
C.	both geometrical and dynamic similarity.
D.	all geometrical, dynamic and kinematic similarity.
Answer» E.

Discussion

2805.	Which law is followed by the velocity distribution in the turbulent boundary layer?
A.	Parabolic law
B.	Linear law
C.	Logarithmic law
D.	None of these
Answer» D. None of these

Discussion

2806.	The losses in open channel flow generally vary as the
A.	inverse of the roughness.
B.	first power of the roughness.
C.	square of the velocity.
D.	inverse square of hydraulic radius.
Answer» C. square of the velocity.

Discussion

2807.	Rise of liquid in a capillary tube is due to
A.	cohesion
B.	adhesion
C.	both (a) & (b)
D.	neither (a) nor (b)
Answer» D. neither (a) nor (b)

Discussion

2808.	The ratio of the wall drag to the form drag in the Stoke's law range (for motion of spherical particles in a stationary fluid) is
A.	0.5
B.	1
C.	2
D.	0.33
Answer» D. 0.33

Discussion

2809.	For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance 'd' measured from the wall of the pipe and the friction velocity 'v', and it follows a __________ relationship.
A.	logarithmic
B.	linear
C.	hyperbolic
D.	parabolic
Answer» B. linear

Discussion

2810.	Maintenance cost of a __________ pump for a particular duty is the least.
A.	centrifugal
B.	reciprocating
C.	volute
D.	gear
Answer» B. reciprocating

Discussion

2811.	Choking in case of pipe flow means that a
A.	specified mass flow rate can not be achieved.
B.	valve is closed in the line.
C.	restriction in flow cross-section area occurs.
D.	none of these.
Answer» B. valve is closed in the line.

Discussion

2812.	Velocity of liquid hydrocarbon fuels in a pipeline can not be measured by magnetic flowmeters, because their __________ is very low/small.
A.	thermal conductivity
B.	electrical conductivity
C.	specific gravity
D.	electrical resistivity
Answer» C. specific gravity

Discussion

2813.	Pascal law is not applicable for a/an __________ fluid.
A.	accelerating frictionless
B.	static
C.	uniformly moving
D.	none of these
Answer» E.

Discussion

2814.	In a fluidised bed reactor
A.	temperature gradients are very high.
B.	temperature is more or less uniform.
C.	hot spots are formed.
D.	segregation of the solids occurs.
Answer» C. hot spots are formed.

Discussion

2815.	The flow of a liquid through tapering pipe at a constant rate is an example of __________ flow.
A.	steady uniform
B.	steady non uniform
C.	unsteady uniform
D.	unsteady non uniform
Answer» C. unsteady uniform

Discussion

2816.	Total reflux in a distillation operation requires minimum
A.	reboiler load
B.	number of plates
C.	condenser load
D.	all (a), (b) and (c)
Answer» C. condenser load

Discussion

2817.	The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by
A.	raising the temperature.
B.	lowering the total pressure.
C.	both (a) and (b).
D.	neither (a) nor (b).
Answer» D. neither (a) nor (b).

Discussion

2818.	The difference of wet bulb temperature and adiabatic saturation temperature of unsaturated mixture of any system is
A.	+ve
B.	-ve
C.	zero
D.	none of these
Answer» B. -ve

Discussion

2819.	Fenske's equation for determining the minimum number of theoretical stages in distillation column holds good, when the
A.	relative volatility is reasonably constant.
B.	mixture (to be separated) shows negative deviation from ideality.
C.	mixture (to be separated) shows positive deviation from ideality.
D.	multicomponent distillation is involved.
Answer» B. mixture (to be separated) shows negative deviation from ideality.

Discussion

2820.	When the temperature and humidity of air is low, we usually use __________ draft cooling tower.
A.	natural
B.	forced
C.	induced
D.	none of these
Answer» B. forced

Discussion

2821.	Overall efficiency of the distillation column is
A.	the ratio of number of ideal plates to actual plates.
B.	the ratio of number of actual plates to ideal plates.
C.	same as the Murphree efficiency.
D.	always more than the point efficiency.
Answer» B. the ratio of number of actual plates to ideal plates.

Discussion

2822.	On addition of solute in the solvent, the __________ of the solution decreases.
A.	boiling point
B.	freezing point
C.	vapour pressure
D.	both (b) and (c)
Answer» E.

Discussion

2823.	Which is the controlling factor for a drum drier?
A.	Diffusion
B.	Heat transfer
C.	Both (a) and (b)
D.	Neither (a) nor (b)
Answer» C. Both (a) and (b)

Discussion

2824.	The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________
A.	1
B.	0.5
C.	10
D.	0
Answer» B. 0.5

Discussion

2825.	Dew point of a gas-vapour mixture
A.	increases with temperature rise.
B.	decreases with temperature rise.
C.	decreases with decrease in pressure.
D.	increases with increase in pressure.
Answer» D. increases with increase in pressure.

Discussion

2826.	In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG __________ the absorption factor.
A.	increases with increase in
B.	is one at unity value of
C.	both (a) and (b)
D.	neither (a) nor (b)
Answer» D. neither (a) nor (b)

Discussion

2827.	Which of the following plays an important role in problems of simultaneous heat and mass transfer ?
A.	Lewis number
B.	Schmidt number
C.	Prandtl number
D.	Sherwood number
Answer» B. Schmidt number

Discussion

2828.	In case of an absorber, the operating
A.	line always lies above the equilibrium curve.
B.	line always lies below the equilibrium curve.
C.	line can be either above or below the equilibrium curve.
D.	velocity is more than the loading velocity.
Answer» B. line always lies below the equilibrium curve.

Discussion

2829.	A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300 C and allowed to cool in natural air. Which one will cool the slowest ?
A.	Cube
B.	Plate
C.	Sphere
D.	All will cool at the same rate
Answer» D. All will cool at the same rate

Discussion

2830.	Vent pipes are provided in a condenser to
A.	remove non-condensable gases.
B.	purge the condenser.
C.	facilitate easy cleaning of tubes.
D.	none of these.
Answer» B. purge the condenser.

Discussion

2831.	Heat transfer by natural convection is enhanced in system with
A.	high viscosity.
B.	high co-efficient of thermal expansion.
C.	low temperature gradients.
D.	low density change with temperature.
Answer» C. low temperature gradients.

Discussion

2832.	In case of __________ boiling, the bubbles formed on a submerged hot surface get absorbed in the mass of the liquid.
A.	nucleate
B.	pool
C.	low pressure
D.	none of these
Answer» C. low pressure

Discussion

2833.	A body cools down from 75 C to 70 C in 10 minutes. It will cool down from 70 C to 65 C in __________ minutes.
A.	10
B.	>10
C.	<10
D.	either (b) or (c), depends on the mass of the body
Answer» C. <10

Discussion

2834.	In forced convection, the Nusselt number is a function of
A.	Re and Pr
B.	Re and Gr
C.	Pr and Gr
D.	Re and Sc
Answer» B. Re and Gr

Discussion

2835.	At what value of Prandtl number, the hydrodynamic and thermal boundary layers are identical ?
A.	0.5
B.	1
C.	1.5
D.	80
Answer» C. 1.5

Discussion

2836.	A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because
A.	total heat transfer area of all the effects is -less than that in a single effect evaporator system.
B.	total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect.
C.	boiling point elevation in a single effect system is much higher than that in any effect in a multieffect system.
D.	heat transfer co-efficient in a single effect is much lower than that in any effect in a multieffect system.
Answer» C. boiling point elevation in a single effect system is much higher than that in any effect in a multieffect system.

Discussion

2837.	__________ equation relates the thermal conductivity of a solid to its temperature.
A.	Antonie
B.	Kopp's
C.	Lee's
D.	Kistyakowski
Answer» D. Kistyakowski

Discussion

2838.	Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.
A.	chemical properties
B.	physical properties
C.	degree of turbulence
D.	interfacial area
Answer» B. physical properties

Discussion

2839.	In a solution containing 0.30 Kg mole of solute and 600 kg of solvent, the molality is
A.	0.50
B.	0.60
C.	2
D.	1
Answer» B. 0.60

Discussion

2840.	Fenske equation determines the
A.	maximum number of ideal plates.
B.	height of the distillation column.
C.	minimum number of theoretical plates.
D.	optimum reflux ratio.
Answer» D. optimum reflux ratio.

Discussion

2841.	The term "cooling range" in a cooling tower refers to the difference in the temperature of
A.	cold water leaving the tower and the wet bulb temperature of the surrounding air.
B.	hot water entering the tower and the wet bulb temperature of the surrounding air.
C.	hot water entering the tower and the cooled water leaving the tower.
D.	none of these
Answer» D. none of these

Discussion

2842.	Which of the following is the most suitable for extraction in a system having very low density difference ?
A.	Mixer-settler extractor
B.	Centrifugal extractor
C.	Pulsed extractor
D.	Packed extraction tower
Answer» C. Pulsed extractor

Discussion

2843.	The Grashoff number is defined as the ratio of the
A.	buoyancy to inertial forces.
B.	buoyancy to viscous forces.
C.	inertial to viscous forces.
D.	buoyancy to surface tension forces.
Answer» C. inertial to viscous forces.

Discussion

2844.	The absorptivity of a body is equal to its emissivity
A.	at a particular temperature.
B.	for circular bodies.
C.	under thermal equilibrium.
D.	none of these.
Answer» D. none of these.

Discussion

2845.	Absorptivity and refletivity of a perfect black body are respectively
A.	1 and 0
B.	0 and 1
C.	1 and
D.	0 and 0.5
Answer» B. 0 and 1

Discussion

2846.	In thermal radiation for a black body (where, is emissivity and is absorptivity)
A.	= 1; 1
B.	1, = 1
C.	1, 1
D.	= 1; = 1
Answer» E.

Discussion

2847.	A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect ?
A.	Vapor compression cycle using expansion valve.
B.	Air refrigeration cycle.
C.	Vapor compression cycle using expansion engine.
D.	Carnot refrigeration cycle.
Answer» E.

Discussion

2848.	In a working refrigerator, the value of COP is always
A.	0
B.	< 0
C.	< 1
D.	> 1
Answer» E.

Discussion

2849.	__________ increases with increase in pressure.
A.	The melting point of wax
B.	The boiling point of a liquid
C.	both (a) and (b)
D.	neither (a) nor (b)
Answer» D. neither (a) nor (b)

Discussion

2850.	Out of the following processes of paper pulp manufacture, the maximum corrosion problem in digestion & handling equipments is encountered in the __________ process.
A.	mechanical
B.	sulphate/kraft
C.	sulphite
D.	neutral sulphite semi-chemical
Answer» E.

Discussion

Explore topic-wise MCQs in Engineering.

A fluid whose apparent viscosity increases with shear rate is termed as the __________ fluid.

Out of the following flow measuring devices, which one incurs the maximum installation cost as well as pressure loss ?

Which of the following has the maximum compression ratio ?

Scale up of agitator design requires

Which law is followed by the velocity distribution in the turbulent boundary layer?

The losses in open channel flow generally vary as the

Rise of liquid in a capillary tube is due to

The ratio of the wall drag to the form drag in the Stoke's law range (for motion of spherical particles in a stationary fluid) is

For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance 'd' measured from the wall of the pipe and the friction velocity 'v', and it follows a __________ relationship.

Maintenance cost of a __________ pump for a particular duty is the least.

Choking in case of pipe flow means that a

Velocity of liquid hydrocarbon fuels in a pipeline can not be measured by magnetic flowmeters, because their __________ is very low/small.

Pascal law is not applicable for a/an __________ fluid.

In a fluidised bed reactor

The flow of a liquid through tapering pipe at a constant rate is an example of __________ flow.

Total reflux in a distillation operation requires minimum

The amount of steam required per unit quantity of distillate in case of steam distillation will be reduced by

The difference of wet bulb temperature and adiabatic saturation temperature of unsaturated mixture of any system is

Fenske's equation for determining the minimum number of theoretical stages in distillation column holds good, when the

When the temperature and humidity of air is low, we usually use __________ draft cooling tower.

Overall efficiency of the distillation column is

On addition of solute in the solvent, the __________ of the solution decreases.

Which is the controlling factor for a drum drier?

The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________

Dew point of a gas-vapour mixture

In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG __________ the absorption factor.

Which of the following plays an important role in problems of simultaneous heat and mass transfer ?

In case of an absorber, the operating

A cube, sphere &amp; a thin circular plate (all having same mass and made of same material) are all heated to 300 C and allowed to cool in natural air. Which one will cool the slowest ?

Vent pipes are provided in a condenser to

Heat transfer by natural convection is enhanced in system with

In case of __________ boiling, the bubbles formed on a submerged hot surface get absorbed in the mass of the liquid.

A body cools down from 75 C to 70 C in 10 minutes. It will cool down from 70 C to 65 C in __________ minutes.

In forced convection, the Nusselt number is a function of

At what value of Prandtl number, the hydrodynamic and thermal boundary layers are identical ?

A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because

__________ equation relates the thermal conductivity of a solid to its temperature.

Mass transfer rate between two fluid phases does not necessarily depend on the __________ of the two phases.

In a solution containing 0.30 Kg mole of solute and 600 kg of solvent, the molality is

Fenske equation determines the

The term "cooling range" in a cooling tower refers to the difference in the temperature of

Which of the following is the most suitable for extraction in a system having very low density difference ?

The Grashoff number is defined as the ratio of the

The absorptivity of a body is equal to its emissivity

Absorptivity and refletivity of a perfect black body are respectively

In thermal radiation for a black body (where, is emissivity and is absorptivity)

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect ?

In a working refrigerator, the value of COP is always

__________ increases with increase in pressure.

Out of the following processes of paper pulp manufacture, the maximum corrosion problem in digestion &amp; handling equipments is encountered in the __________ process.

A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300 C and allowed to cool in natural air. Which one will cool the slowest ?

Out of the following processes of paper pulp manufacture, the maximum corrosion problem in digestion & handling equipments is encountered in the __________ process.