chemical engineering Mcqs
6251. Which of the following relationship is valid for the equilibrium position of the float in a Rotameter? (Where, Df= Drag force on the float Bf = Buoyant force on the float Wf = Weight of the float)?
comments icon0
A. Df + Bf = Wf

B. None of these

C. Df + Bf + Wf =0

D. Df = Bf + Wf

6252. Addition of grog in fireclay brick during its manufacture is advantageous, because it results in_____________________?
comments icon0

A. ractories and hence increased rate of production

B. All A., B. and C.

C. Less addition of water to get a workable plasticity & lesser time required for drying the raw

D. High strength & thermal spalling resistance

E. Less shrinkage in heating, decreased apparent porosity & increased specific gravity

6253. In case of a pipe exit fitted with a nozzle, the____________________?
comments icon0

A. Conversion of kinetic head to pressure head is facilitated

B. Conversion of pressure head to kinetic head is facilitated

C. Power transmitted through the nozzle is maximum, when the head lost due to friction in the

D. e is equal to one third of the total supply head

E. Both B. and C.
6254. High alumina refractory compared to fireclay bricks have____________________?
comments icon0

A. Less load bearing capacity

B. Low refractoriness

C. High resistance to thermal shock and creep

D. Less resistance to slag attack

6255. Fusion temperature of pure silica (SiO2) is _______________ C?
comments icon0
A. 1715

B. 2570

C. 1350

D. 2800

6256. Pyrometric cone equivalent (PCE) of a refractory is the measure of its_________________?
comments icon0

A. Resistance to carbon monoxide attack

B. Resistance to slag penetration

C. Fusion point

D. Spalling resistance

6257. Lower BWG means _____________ of the tube?
comments icon0

A. Lower thickness

B. Outer diameter

C. Lower cross-section

D. Inner diameter

6258. Which is not a high alumina refractory ?
comments icon0

A. Corundum

B. Mullite

C. Dolomite

D. Bauxite

6259. Critical velocity in a pipe flow_________________?
comments icon0
A. Increases as pipe diameter increases

B. Increases as fluid viscosity increases

C. Independent of fluid density

D. None of these

6260. Vacuum steel degassing units are lined with__________________?
comments icon0

A. Silica bricks

B. High alumina bricks

C. Graphite blocks

D. Low duty firebricks

6261. A piezometer provided in the pipe measures__________________?
comments icon0

A. Friction factor

B. Static pressure

C. None of these

D. Dynamic pressure

6262. Which is not a natural insulating material ?
comments icon0

A. Vermiculite

B. Asbestos

C. Diatomaceous earth/kieselgur

D. None of these
6263. The percentage slip in a reciprocating pump set is given by the % of (where, Q1 = actual discharge Q2 = theoretical discharge) ?
comments icon0

A. Q1/Q2

B. (Q2 Q1)/Q2

C. (Q2 Q1)/Q1

D. Q2/Q1

6264. For turbulent fluid flow in pipe, the expression for Prandtl one seventh power law is (where, r = pipe radius, x = distance) ?
comments icon0

A. V/Vmax = (r/x)1/7

B. V/Vmax = (x.r)1/7

C. None of these

D. V/Vmax = (x/r)1/7
6265. Slugging occurs in a fluidised bed, if the bed is___________________?
comments icon0

A. Narrow

B. Deep

C. Both A. & B.

D. Neither A. nor B.

6266. Piezometric head is the sum of the ______________ heads?
comments icon0

A. Kinetic energy & pressure

B. Elevation & pressure

C. Elevation & kinetic energy

D. None of these

6267. Gradually varying fluid flow is an example of ____________ flow?
comments icon0

A. Steady uniform

B. Steady non-uniform

C. Non-steady non-uniform

D. Non-steady uniform
6268. Hydraulic _____________ works on the principle of Pascals law of transmission of fluid pressure?
comments icon0

A. Coupling

B. Turbine

C. Pump

D. Press
6269. Two piping system are said to be equivalent, when the ______________ are same?
comments icon0

A. Length & diameter

B. Length & friction factor

C. Diameter & friction factor

D. Fluid flow rate & friction loss
6270. In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity)?
comments icon0

A. 1.8 Vavg

B. Vavg

C. 1.5 Vavg

D. 1.2 Vavg
6271. Shear stress in a fluid flowing in a round pipe_________________?
comments icon0

A. Remains constant over the cross-section

B. Varies parabolically across the cross-section

C. Is zero at the centre and varies linearly with the radius

D. Is zero at the wall and increases linearly to the centre

6272. For a stable equilibrium of a submerged body (where, G and B are centres of gravity & buoyancy respectively) ?
comments icon0

A. None of these

B. G is above B

C. B is above G

D. B & G coincide

6273. The frictional resistance in laminar flow does not depend on the_________________?
comments icon0

A. Flow velocity

B. Pressure of flow

C. Fluid temperature

D. Area of surface in contact
6274. A hydraulic press has a ram of 10 cms in diameter and a plunger of 1 cm in diameter. The force required on the plunger to raise a weight of 10 tons on the ram is _____________ kg?
comments icon0
A. 100

B. 1000

C. 10

D. 10000

6275. An ideal plastic substance indicates no deformation, when stressed upto yield stress, but behaves like a Newtonian fluid beyond yield stress. Which of the following is an ideal plastic ?
comments icon0
A. Sewage sludge

B. Rubber latex

C. Blood

D. Sugar solution

6276. 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 power consumed now will be _____________ hp?
comments icon0

A. 2

B. 1

C. 4

D. 0.5
6277. Which is the correct relationship for a centrifugal pump? (Where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm) ?
comments icon0

A. H = 1840 D0.5/N

B. D = 1840 H0.5/N

C. D = 1840 N/H0.5

D. D = 1840 H/N

6278. For the transfer of solution of thick slurry, the pump used is a _____________ pump?
comments icon0

A. Centrifugal

B. Diaphragm

C. Reciprocating

D. Gear

6279. What is the unit of kinematic viscosity in SI unit ?
comments icon0

A. None of these

B. M2/sec

C. Kg. sec/m

D. N/m2. sec

6280. A fluid element has a velocity V = -y2. xi + 2yx2 . j. The motion at (x, y) = (1/?2, 1) is_________________?
comments icon0

A. Rotational and incompressible

B. Irrotational and compressible

C. Rotational and compressible

D. Irrotational and incompressible

6281. The time of oscillation of a floating body is _________________?
comments icon0
A. None of these

B. Longer, if Metacentric height is increased

C. Dependent on the buoyant forces only

D. Independent of the Metacentric height

6282. Out of the following flow measuring devices, which one incurs the maximum installation cost as well as pressure loss ?
comments icon0

A. Orificemeter

B. Rotameter

C. Flow nozzle

D. Venturimeter
6283. Boundary layer exists in flow_________________?
comments icon0

A. In pipes only

B. Over flat surfaces only

C. Of ideal fluids only

D. Of real fluids
6284. Gear pump_________________?
comments icon0

A. Is a non-positive displacement pump

B. Can be started with delivery valve closed

C. Is a positive displacement pump

D. Is a centrifugal pump

6285. The discharge through a semi-circular weir varies as (where, H = Head of liquid.) ?
comments icon0

A. H3/2

B. H2

C. H

D. H1/2

6286. A bed of spherical particles (specific gravity 2.5) of uniform size 1500 ?m is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Erguns equation for the above fluid-particle system (in SI units) is given below : ? P/L = 375 103 VOM + 10.94 106 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is_________________?
comments icon0

A. 24 mm/s

B. 28 mm/s

C. 16 mm/s

D. 12 mm/s

6287. Boundary layer separation is caused by the ____________________?
comments icon0

A. Reduction of pressure below vapour pressure

B. Reduction of boundary layer thickness to zero

C. Adverse pressure gradient

D. Reduction of pressure gradient to zero

6288. Pressure drag does not depend upon the_________________?
comments icon0
A. All A., B. and C.

B. Length of the body in flow direction

C. Pressure of main flow only

D. Roughness of surface of the body

6289. Pump used for the transportation of molten sodium in a fast breader reactor is a/an __________ pump?
comments icon0

A. Gear

B. Electromagnetic

C. Reciprocating

D. Plunger

6290. A Newtonian fluid is that__________________?
comments icon0

A. Which needs a minimum shear, before it starts deforming

B. Which follows Newtons law of motion

C. For which shear & deformation are related as T = ? (?u/?y)

D. None of these

6291. Mass velocity is independent of temperature & pressure, when the flow is______________________?
comments icon0
A. Steady and the cross-section is unchanged

B. Steady through changing cross-section

C. Unsteady through unchanged cross-section

D. Unsteady and the cross-section is changed

6292. Upto what value of Mach number, a fluid may be considered as incompressible ?
comments icon0

A. 0.03

B. 3

C. 0.3

D. 10

6293. A 2? gate valve fitted in a pipe is replaced by a similar globe valve. Pressure drop in gate valve was ?p. For the same discharge, the pressure drop across globe valve is__________________?
comments icon0

A. < ?p

B. > ?p

C. ?p

D. ?p2

6294. Bernoullis equation accounts for the_____________________?
comments icon0

A. Various momentums

B. Various masses

C. None of these

D. Different forms of mechanical energy
6295. Which of the following equations applies to the fluid flow through a packed bed for very large Reynolds number ?
comments icon0

A. Hagen-Poiseuille equation

B. Kozeny-Carman equation

C. Blake-Plummer equation

D. Fanning equation

6296. Froude number is the ratio of__________________?
comments icon0

A. Inertial stress to shear stress

B. Drag stress to shear stress

C. Shear stress to gravitational stress

D. Inertial stress to gravitational stress
6297. The main factor on which the behaviour of a mass of fluidised solid depends mainly is the___________________?
comments icon0

A. Fluid characteristics

B. Particle size

C. Both A. and B.

D. Neither A. nor B.

6298. Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about__________________?
comments icon0
A. 0.62

B. 0.82

C. 0.98

D. 0.42

6299. A stream tube is that, which has ______________________ cross-section entirely bounded by stream lines?
comments icon0

A. A small

B. A circular

C. Any convenient

D. A large

6300. 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____________________?
comments icon0
A. Q/16

B. Q/8

C. Q/4

D. Q/2