908 + Mcqs in Process Equipment And Plant Design Page 1 McqOptions

1.	With increase in temperature drop (in a shell and tube heat exchanger), the correction factor,
A.	decreases very rapidly
B.	increases very rapidly
C.	remains constant
D.	increases linearly
Answer» B. increases very rapidly

Discussion

2.	In a double pipe concentric heat exchanger, the equivalent diameter of annulus for heat transfer would be (where, and are I.D. of inner and outer pipes)
A.	-
B.	none of these
Answer» B. none of these

Discussion

3.	Joint efficiency () for a seamless pipe is
A.	1
B.	0.85
C.	1.2
D.	< 0.5
Answer» B. 0.85

Discussion

4.	In common bubble cap distillation column design practice, riser area is approximately equal to (where, = Annular passage area, and = Slot area)
A.	=
B.	1.2
C.	= 1.2
D.	= 1.5
E.	= 1.5
Answer» B. 1.2

Discussion

5.	The absorption factor is defined as (where, = slope of the equilibrium curve, = slope of the operating line)
A.	/
B.	.
C.	/
D.	1/
E.	.
Answer» B. .

Discussion

6.	In the design of a paddle agitator, the ratiois normally taken as
A.	0.1
B.	0.8
C.	0.25
D.	0.5
Answer» C. 0.25

Discussion

7.	Stress-strain diagram for low carbon steel/mild steel is shown below in the Fig. The point '' on the Fig. represents the
A.	breaking stress
B.	ultimate stress
C.	elastic limit
D.	yield point
Answer» D. yield point

Discussion

8.	In a multiple effect evaporator system having '' effects, the amount of water evaporated per unit surface area in approximately equal to __________ times that in a single effect.
A.	'n'th
B.	(1/n)th
C.	0.5 nth
D.	1.5 nth
Answer» C. 0.5 nth

Discussion

9.	The correction factor () is applied in __________ heat exchangers.
A.	1-1 cocurrent
B.	double pipe
C.	all multipass
D.	all (involving liquid/liquid heat transfer)
Answer» D. all (involving liquid/liquid heat transfer)

Discussion

10.	for couplings and unions would be
A.	60
B.	200
C.	350
D.	negligible
Answer» E.

Discussion

11.	The equivalent diameter for fluid flow through a channel of constant non-circular cross section of area '' is given by (where, = perimeter of the channel in contact with the fluid)
A.	4
B.	/
C.	/
D.	4
E.	/
Answer» B. /

Discussion

12.	The raio, is normally taken as
A.	0.15-030
B.	0.5-0.65
C.	0.75-0.85
D.	0.60-0.90
Answer» B. 0.5-0.65

Discussion

13.	For pipe flows, head is proportional to __________ at constant capacity (where = pipe diameter ).
A.	1/
B.	1/
C.	1/
Answer» D.

Discussion

14.	Friction factor for turbulent flow in a new pipe is given by
A.	= 0.22
Answer» C.

Discussion

15.	The approximate liquid depth in an agitation tank is equal to (where, = tank diameter)
A.	0.5
B.	0.75
C.	2
Answer» D.

Discussion

16.	A cylinderical pressure vessel of volume 6 πm has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to
A.	5 mm
B.	6 mm
C.	8 mm
D.	10 mm
Answer» E.

Discussion

17.	What is the value of '' for saturated vapor feed to a distillation column ?(where = fraction of the feed stream that is liquid.)
A.	0
B.	1
C.	<0
D.	> 1
Answer» B. 1

Discussion

18.	In case of plain carbon steel, butt welded joints are used for shell plate thickness ≤ __________ cms.
A.	1.2
B.	0.5
C.	3.8
D.	6.8
Answer» D. 6.8

Discussion

19.	In case of a shell and tube heat exchanger, the effect of / on inside film heat transfer co-efficient () vanishes after a Reynold number of
A.	1000
B.	3000
C.	5000
D.	10000
Answer» E.

Discussion

20.	Souders Brown equation given by, , is used for the calculation of the __________ in a continuous distillation column.
A.	diameter of the bubble cap column
B.	diameter of the seive plate column
C.	tray pressure drop
D.	residence time in the downcomer for the disengagement of entrained vapour
Answer» B. diameter of the seive plate column

Discussion

21.	The safe height () to diameter () ratio (i.e., /) for liquid/petro fuel storage tank of capacity more than 45 kilolitres is less than
A.	1
B.	2
C.	3
D.	3.5
Answer» B. 2

Discussion

22.	Steam is defined as the amount of evaporation per unit amount of steam used, while the is the total evaporation obtained per hour. Use of multiple effect in evaporation
A.	increases capacity.
B.	increases economy.
C.	does not affect the capacity.
D.	both 'b' & 'c'.
Answer» E.

Discussion

23.	Elastic failure of a material occurs, when the tensile stress equals yield strength, yield point or the elastic limit. Also, the elastic failure occurs according to maximum strain theory, when the maximum tensile strain equals (where, σ = yield strength and = modulus of elasticity)
A.	σ
B.	σ/
C.	/σ
Answer» D.

Discussion

24.	Diameter of rivet hole (, mm) and the plate thickness (, mm) are related by Unwin's formula as
A.	= 1.1
B.	= 1.6
C.	= 1.5
D.	3
Answer» C. = 1.5

Discussion

25.	Heat transfer co-efficient, (K/hr.m .°C) and mass velocity of air, (kg/hr.m ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as = 0.0176. But when the flow of air perpendicular to the surface is encountered, this equation changes to
A.	= 1.004
B.	1.004
C.	hG = 0.0176
D.	0.0176
Answer» B. 1.004

Discussion

26.	In a shell and tube heat exchanger having square pitch, the shell side equivalent diameter is given by (where, = pitch, = outside diameter of the tube)
A.	π
B.	/4
Answer» B. /4

Discussion

27.	Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, = shell diameter )
A.	0.2
B.	0.5
C.	0.66
D.	0.80
Answer» B. 0.5

Discussion

28.	Pressure drop due to pipe fittings can be estimated by the equation, , where, = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and = diameter of the fitting. The value of (dimensionless) for 45° elbow and 180° close return bends would be respectively around
A.	5 and 10
B.	45 and 75
C.	180 and 300
D.	300 and 500
Answer» C. 180 and 300

Discussion

29.	In a shell and tube heat exchanger, the overall heat transfer co-efficient is proportional to the tube side (volumetric flow rate). This is valid, only when the ratio of the tube side film resistance to the total resistance is almost equal to
A.	∞
B.	1
C.	20.8
D.	2
Answer» C. 20.8

Discussion

30.	Pick out the wrong statement.In an agitated vertical cylinderical reaction vessel, the
A.	ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1.
B.	filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period.
C.	flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids.
D.	dished bottom vessel has very high power consumption.
Answer» E.

Discussion

31.	What is the value of '' for saturated liquid feed to a distillation column ?
A.	0
B.	<1
C.	1
D.	>1
Answer» D. >1

Discussion

32.	Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about __________ kcal/hr.m.°C.
A.	1250
B.	2500
C.	7500
D.	15000
Answer» D. 15000

Discussion

33.	It is not desirable to design a heat exchanger for correction factor, , of less than
A.	0.99
B.	0.95
C.	0.80
D.	0.55
Answer» D. 0.55

Discussion

34.	Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 - 1.4 cp and relative volatility < 4) (where η = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δ = pressure drop per tray, psi)
A.	η = 17 - 61.1 log μ
B.	η = 1.66 - 0.25 log μ
C.	η = 0.25 log μ - 1.67
Answer» B. η = 1.66 - 0.25 log μ

Discussion

35.	With increase in the number of shell passes, the value of
A.	increases
B.	decreases
C.	remains same
D.	remains same, only if the number of tube passes does not change.
Answer» B. decreases

Discussion

36.	A cylinderical pressure vessel of volume 6 πm3 has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm2 and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to
A.	5 mm
B.	6 mm
C.	8 mm
D.	10 mm
Answer» E.

Discussion

37.	In a cylinderical vessel subjected to internal pressure, the longitudinal stress σL and the circumferential stress, σn are related by
A.	σh = 2 σL
B.	σh = σL
C.	σh = σL/2
D.	no relation exists
Answer» B. σh = σL

Discussion

38.	Heat transfer co-efficient, hG(Kcal/hr.m2 .°C) and mass velocity of air, G (kg/hr.m2 ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to
A.	hG = 1.004G0.37
B.	1.004G0.8
C.	hG = 0.0176G0.37
D.	0.0176G1.37
Answer» B. 1.004G0.8

Discussion

39.	Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about __________ kcal/hr.m2.°C.
A.	1250
B.	2500
C.	7500
D.	15000
Answer» D. 15000

Discussion

40.	In a rotary drier, the average retention time of solid is(where Z = length of the drier, metres ρ = apparent solid density, kg/m3 L = flow rate of dry solids, kg/see. m2 drier cross-section H = hold up of solid.)
A.	[A].
B.	[B].
C.	[C].
D.	[D].
Answer» B. [B].

Discussion

41.	For turbulent flow (NRe > 2100) of low viscosity fluid (μ > 20cp) in steel pipes, the optimum inside pipe diameter is given by(where, Q = fluid flow rate, ft3/sec.ρ = fluid density, lb/ft3 μ = fluid viscosity, centipoise Di = optimum inside pipe diameter, inches)
A.	Di, opt = 3.9 Q0.45 ρ0.13
B.	Di, opt = 3.9 Q0.45 . μ0.95
C.	Di, opt = 4.7 Q0.36 . μ3.2ρ0.13
D.	Di, opt = 3 Q0.36 . μ0.88
Answer» B. Di, opt = 3.9 Q0.45 . μ0.95

Discussion

42.	for 90° elbow (medium radius) and 90°square elbow would be respectively around
A.	25 and 60
B.	3 and 5
C.	100 and 250
D.	250 and 600
Answer» B. 3 and 5

Discussion

43.	Pressure drop due to pipe fittings can be estimated by the equation, , where, Le = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of (dimensionless) for 45° elbow and 180° close return bends would be respectively around
A.	5 and 10
B.	45 and 75
C.	180 and 300
D.	300 and 500
Answer» C. 180 and 300

Discussion

44.	In case of plain carbon steel, butt welded joints are used for shell plate thickness ≤ __________ cms..
A.	0.2
B.	0.5
C.	0.8
D.	0.8
Answer» D. 0.8

Discussion

45.	Pressure drop due to pipe fittings can be estimated by the equation, ΔP/p = 4f.Le/D.V2/2gc, where, Le = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of Le/D (dimensionless) for 45° elbow and 180° close return bends would be respectively around
A.	and 10
B.	5 and 75
C.	80 and 300
D.	00 and 500
Answer» C. 80 and 300

Discussion

46.	Which of the following factors affect the pressure drop in a co-current gas-liquid absorption packed tower?
A.	ize, shape, orientation and surface of the packing particles
B.	ensity and viscosity of fluids
C.	luid flow rates
D.	ll of the above
Answer» E.

Discussion

47.	The centre to centre distance between two consecutive baffles in a shell and tube heat exchanger is called the baffle pitch or baffle spacing, which is more than 1/5th the I.D. of the shell. Which of the following is not a function of the baffles?
A.	o increase the residence time of shell side fluid
B.	o provide support to the tube bundle
C.	o reduce the induced vibration in the tubes
D.	o increase the tube side heat transfer co-efficient by inducing turbulence
Answer» E.

Discussion

48.	The clearance between two tubes in a shell and tube heat exchanger is known as 'ligament', whose minimum value is __________ the outside diameter of the tube, but in no case it should be less than 4.5 mm.
A.	qual to
B.	alf
C.	ne fourth
D.	hree fourth
Answer» D. hree fourth

Discussion

49.	For a cylinderical vessel of moderate height, the weld joint efficiency for joints parallel to the cylinderical axis is given as 1.0, while for joints along the girth (circumference) it is given as 0.8. In calculating the shell wall thickness using code formula for an internally pressurised cylinderical vessel, what value of weld joint efficiency should be used?
A.	0.8
B.	0.9
C.	0
D.	0.8)0.5
Answer» B. 0.9

Discussion

50.	Heat transfer co-efficient, hG(Kcal/hr.m² .°C) and mass velocity of air, G (kg/hr.m² ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to
A.	G = 1.004G0.37
B.	.004G0.8
C.	G = 0.0176G0.37
D.	.0176G1.37
Answer» B. .004G0.8

Discussion

Explore topic-wise MCQs in Chemical Engineering.

With increase in temperature drop (in a shell and tube heat exchanger), the correction factor,

In a double pipe concentric heat exchanger, the equivalent diameter of annulus for heat transfer would be (where, and are I.D. of inner and outer pipes)

Joint efficiency () for a seamless pipe is

In common bubble cap distillation column design practice, riser area is approximately equal to (where, = Annular passage area, and = Slot area)

The absorption factor is defined as (where, = slope of the equilibrium curve, = slope of the operating line)

In the design of a paddle agitator, the ratiois normally taken as

Stress-strain diagram for low carbon steel/mild steel is shown below in the Fig. The point '' on the Fig. represents the

In a multiple effect evaporator system having '' effects, the amount of water evaporated per unit surface area in approximately equal to __________ times that in a single effect.

The correction factor () is applied in __________ heat exchangers.

for couplings and unions would be

The equivalent diameter for fluid flow through a channel of constant non-circular cross section of area '' is given by (where, = perimeter of the channel in contact with the fluid)

The raio, is normally taken as

For pipe flows, head is proportional to __________ at constant capacity (where = pipe diameter ).

Friction factor for turbulent flow in a new pipe is given by

The approximate liquid depth in an agitation tank is equal to (where, = tank diameter)

A cylinderical pressure vessel of volume 6 πm has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to

What is the value of '' for saturated vapor feed to a distillation column ?(where = fraction of the feed stream that is liquid.)

In case of plain carbon steel, butt welded joints are used for shell plate thickness ≤ __________ cms.

In case of a shell and tube heat exchanger, the effect of / on inside film heat transfer co-efficient () vanishes after a Reynold number of

Souders Brown equation given by, , is used for the calculation of the __________ in a continuous distillation column.

The safe height () to diameter () ratio (i.e., /) for liquid/petro fuel storage tank of capacity more than 45 kilolitres is less than

Steam is defined as the amount of evaporation per unit amount of steam used, while the is the total evaporation obtained per hour. Use of multiple effect in evaporation

Elastic failure of a material occurs, when the tensile stress equals yield strength, yield point or the elastic limit. Also, the elastic failure occurs according to maximum strain theory, when the maximum tensile strain equals (where, σ = yield strength and = modulus of elasticity)

Diameter of rivet hole (, mm) and the plate thickness (, mm) are related by Unwin's formula as

Heat transfer co-efficient, (K/hr.m .°C) and mass velocity of air, (kg/hr.m ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as = 0.0176. But when the flow of air perpendicular to the surface is encountered, this equation changes to

In a shell and tube heat exchanger having square pitch, the shell side equivalent diameter is given by (where, = pitch, = outside diameter of the tube)

Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, = shell diameter )

In a shell and tube heat exchanger, the overall heat transfer co-efficient is proportional to the tube side (volumetric flow rate). This is valid, only when the ratio of the tube side film resistance to the total resistance is almost equal to

Pick out the wrong statement.In an agitated vertical cylinderical reaction vessel, the

What is the value of '' for saturated liquid feed to a distillation column ?

Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about __________ kcal/hr.m.°C.

It is not desirable to design a heat exchanger for correction factor, , of less than

Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 - 1.4 cp and relative volatility < 4) (where η = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δ = pressure drop per tray, psi)

With increase in the number of shell passes, the value of

A cylinderical pressure vessel of volume 6 πm3 has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm2 and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to

In a cylinderical vessel subjected to internal pressure, the longitudinal stress σL and the circumferential stress, σn are related by

Heat transfer co-efficient, hG(Kcal/hr.m2 .°C) and mass velocity of air, G (kg/hr.m2 ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to

Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about __________ kcal/hr.m2.°C.

In a rotary drier, the average retention time of solid is(where Z = length of the drier, metres ρ = apparent solid density, kg/m3 L = flow rate of dry solids, kg/see. m2 drier cross-section H = hold up of solid.)

For turbulent flow (NRe > 2100) of low viscosity fluid (μ > 20cp) in steel pipes, the optimum inside pipe diameter is given by(where, Q = fluid flow rate, ft3/sec.ρ = fluid density, lb/ft3 μ = fluid viscosity, centipoise Di = optimum inside pipe diameter, inches)

for 90° elbow (medium radius) and 90°square elbow would be respectively around

In case of plain carbon steel, butt welded joints are used for shell plate thickness ≤ __________ cms..

Which of the following factors affect the pressure drop in a co-current gas-liquid absorption packed tower?

The centre to centre distance between two consecutive baffles in a shell and tube heat exchanger is called the baffle pitch or baffle spacing, which is more than 1/5th the I.D. of the shell. Which of the following is not a function of the baffles?

The clearance between two tubes in a shell and tube heat exchanger is known as 'ligament', whose minimum value is __________ the outside diameter of the tube, but in no case it should be less than 4.5 mm.