MCQOPTIONS
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MCQOPTIONS
This section includes 74 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Characteristic curves for a centrifugal pump plotted against its capacity is shown in the diagram. x, y and z denote respectively |
| A. | efficiency, head and B.H.P. |
| B. | head, efficiency and B.H.P. |
| C. | B.H.P., efficiency and head |
| D. | efficiency, B.H.P. and head |
| Answer» C. B.H.P., efficiency and head | |
| 52. |
C d is always __________ C c . |
| A. | greater than |
| B. | less than |
| C. | equal to |
| D. | either more or less than |
| Answer» B. less than | |
| 53. |
A pressure head of 320 metres of water in meters of CCl 4 (sp.gr = 1.6) will be |
| A. | 100 |
| B. | 200 |
| C. | 320 |
| D. | 160 |
| Answer» C. 320 | |
| 54. |
A pressure of 10 m head of water is equivalent to __________ kN/m 2 . |
| A. | 98 |
| B. | 147 |
| C. | 196 |
| D. | 49 |
| Answer» B. 147 | |
| 55. |
A centrifugal pump is used to pump water through a horizontal distance of 150 m, and then raised to an overhead tank 10 m above. The pipe is smooth with an I.D of 50 mm. What head (m of water) must the pump generate at its exit (E) to deliver water at a flow rate of 0.001 m 3 /s? The Fanning friction factor, f is 0.0062. |
| A. | 10 m |
| B. | 11 m |
| C. | 12 m |
| D. | 20 m |
| Answer» C. 12 m | |
| 56. |
What is the shear rate at the pipe wall, in case of laminar flow of Newtonion fluids in a pipe of diameter ' D ' & length ' L ' incurring a pressure drop '? p ' with average velocity ' V avg '? |
| A. | D ? p /8 L |
| B. | D ? p /4 L |
| C. | 8 . V avg / D |
| D. | 4 . V avg / D |
| Answer» D. 4 . V avg / D | |
| 57. |
N 2 Re / N Fr is called the __________ number. |
| A. | Brinkman |
| B. | Galileo |
| C. | Archimedes |
| D. | Euler |
| Answer» C. Archimedes | |
| 58. |
A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpm Head = 8 metres Flow = 1000 litres/minutes. If its speed is halved, the new discharge will be __________ litres/minute. |
| A. | 500 |
| B. | 200 |
| C. | 1000 |
| D. | 750 |
| Answer» B. 200 | |
| 59. |
Viscosity of water at 40°C lies in the range of |
| A. | 1 x 10 -3 to 2 x 10 -3 kg/m.s |
| B. | 0.5 x 10 -3 to 1 x 10 -3 kg/m.s |
| C. | 1 to 2 kg/m.s |
| D. | 0.5 to 1 kg/m.s |
| Answer» C. 1 to 2 kg/m.s | |
| 60. |
For turbulent flow of an incompressible fluid through a pipe, the flow rate Q is proportional to (? P)n, where ?P is the pressure drop. The value of exponent 'n' is |
| A. | 1 |
| B. | 0 |
| C. | < 1 |
| D. | > 1 |
| Answer» D. > 1 | |
| 61. |
The variable required to be known in correlations used for estimating the horse power of a centrifugal gas compressor and hence its cost are P. Inlet pressure Q. Compressor rpm R. Delivery pressure S. Volumetric flow rate at inlet. |
| A. | P, Q and R |
| B. | P and R |
| C. | R and S |
| D. | P, Rand S |
| Answer» B. P and R | |
| 62. |
C d , C c and C v are related (for flow through an orifice) as (where, C d = discharge co-efficient C c = co-efficient of contraction C v = co-efficient of velocity ) |
| A. | C d = Cc / C v |
| B. | C d = C c . C v |
| C. | C d = C v / cc |
| D. | none of these |
| Answer» C. C d = C v / cc | |
| 63. |
Applying a pressure drop across a capillary results in a volumetric flow rate ' Q ' under laminar flow conditions. The flow rate for the same pressure drop, in a capillary of the same length but half the radius is |
| A. | Q /2 |
| B. | Q /4 |
| C. | Q /8 |
| D. | Q /16 |
| Answer» E. | |
| 64. |
A fluid element has a velocity V = -y 2 . xi + 2yx 2 . j. The motion at (x, y) = (l/ 2 , 1) is |
| A. | rotational and incompressible |
| B. | rotational and compressible |
| C. | irrotational and compressible |
| D. | irrotational and incompressible |
| Answer» C. irrotational and compressible | |
| 65. |
The energy equation, (E = internal energy/mass), is applicable to |
| A. | perfect gases only. |
| B. | isothermal flow of gases. |
| C. | adiabatic unsteady flow of gases. |
| D. | all compressible fluids. |
| Answer» E. | |
| 66. |
For a given Reynold number as d / D for an orifice increases, C d will (where, d & D are orifice & pipe diameters respectively). |
| A. | increase |
| B. | decrease |
| C. | remain constant |
| D. | either (a) or (b); depends on other factors |
| Answer» B. decrease | |
| 67. |
For the free settling of a spherical particle through a fluid, the slope of, C D -log N Re , plot is |
| A. | 1 |
| B. | -1 |
| C. | 0.5 |
| D. | -0.5 |
| Answer» C. 0.5 | |
| 68. |
Vena-contracta pressure tapping is at a distance __________ from the position of an orificemeter fitted in a pipe of internal diameter ' d ' |
| A. | d |
| B. | 0.5 d |
| C. | 2 d |
| D. | 4 d |
| Answer» C. 2 d | |
| 69. |
Three piping networks as shown in the figure are placed horizontally. They are made using identical pipe segments and are subjected to the same pressure drop across them. Assuming no pressure losses at junctions, the flow rates across the three networks are related as Q 1 : Q 2 : Q 3 . |
| A. | 1: 3 : 2 |
| B. | 1:2:3 |
| C. | 1:2:2 |
| D. | 1: 2 : 2 |
| Answer» D. 1: 2 : 2 | |
| 70. |
Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be __________ ft. |
| A. | 40 |
| B. | 34 |
| C. | 8 |
| D. | 37 |
| Answer» D. 37 | |
| 71. |
For Laminar flow through a packed bed, the pressure drop is proportional to ( V s is the superficial liquid velocity and D p is the particle diameter) |
| A. | V s / D p 2 |
| B. | V s 2 / D p 2 |
| C. | V s 2 / Dp 3 |
| D. | V s / D p 3 |
| Answer» B. V s 2 / D p 2 | |
| 72. |
The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10 -6 m 2 /s). |
| A. | 24000 |
| B. | 24 |
| C. | 0.24 |
| D. | 0.44 |
| Answer» E. | |
| 73. |
The terminal velocity of a particle moving through a fluid varies as d p n . What is the value of n' for Newton's law regime ? |
| A. | 0.5 |
| B. | 1 |
| C. | 1.5 |
| D. | 3 |
| Answer» B. 1 | |
| 74. |
Hydraulic mean depth ( D m ) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at D m = 0.3 D, gives the condition for the maximum |
| A. | flow rate |
| B. | mean velocity |
| C. | both 'a' & 'b' |
| D. | neither 'a' nor 'b' |
| Answer» C. both 'a' & 'b' | |