chemical engineering fluid mechanics for chemical chemical engineering Mcqs
251. At high Reynolds number_________________?
comments icon0
A. Inertial forces control and viscous forces are unimportant

B. Viscous forces predominate

C. Inertial forces are unimportant and viscous forces control

D. None of these

252. One dimensional flow implies________________________?
comments icon0
A. A flow which does not account for changes in transverse direction

B. Unsteady uniform flow

C. Steady uniform flow

D. Flow in a straight line

253. Steady non-uniform flow is exemplified by flow through a/an___________________?
comments icon0

A. Expanding tube at increasing rate

B. Expanding tube at constant rate

C. Long pipe at constant rate

D. Long pipe at decreasing rate

254. Froude number is the ratio of__________________?
comments icon0
A. Inertial stress to gravitational stress

B. Inertial stress to shear stress

C. Shear stress to gravitational stress

D. Drag stress to shear stress

255. Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the______________?
comments icon0

A. Wall roughness

B. Reynolds number

C. Both A. & B.

D. Neither A. nor B.

256. A Venturimeter measures the___________________?
comments icon0

A. Point velocity

B. Velocity head

C. Pressure

D. None of these
257. 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.

258. Pressure drag does not depend upon the_________________?
comments icon0

A. Pressure of main flow only

B. All A., B. and C.

C. Length of the body in flow direction

D. Roughness of surface of the body

259. While starting an axial flow pump, its delivery valve should be kept _______________?
comments icon0

A. Closed

B. Open

C. Either open or closed

D. None of these

260. Kinetic energy of fluid per unit weight represented by the velocity head is given by___________________?
comments icon0
A. v2/2gc

B. ?.v2/2gc

C. 2v2/gc

D. ?v2/gc

261. Most commonly used joint in the underground pipe lines is the________________?
comments icon0

A. Coupling

B. Sleeve joint

C. Flange

D. Expansion joint

262. Paper pulp is an example of _____________ fluid?
comments icon0
A. Bingham plastic

B. Dilatant

C. Newtonian

D. Pseudo-plastic

263. A fluid is a substance, that_________________?
comments icon0

A. Has zero shear stress

B. Has to be kept in a closed container

C. Flows when even a small shear is applied to it

D. Is almost incompressible

264. What is the speed of sound (m/sec) in ordinary water ?
comments icon0

A. 1000

B. 3000

C. 330

D. 1500
265. The component of acceleration resulting due to unsteady nature of flow is called ____________ acceleration?
comments icon0

A. Normal

B. Tangential

C. Convective

D. Local
266. Higher specific speed (200-500) of a centrifugal pump indicates that the pump is of ______________ flow type?
comments icon0
A. Axial

B. Radial

C. Mixed

D. None of these

267. Differential manometer measures the____________________?
comments icon0

A. None of these

B. Atmospheric pressure

C. Pressure difference between two points

D. Sub-atmospheric pressure

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

A. Fluid temperature

B. Pressure of flow

C. Area of surface in contact

D. Flow velocity

269. Minimum porosity for fluidisation is____________________?
comments icon0

A. That corresponding to completely fluidised bed

B. That corresponding to static bed

C. Less than that of the static bed

D. The porosity of the bed when true fluidisation begins
270. For the transfer of solution of thick slurry, the pump used is a _____________ pump?
comments icon0
A. Diaphragm

B. Reciprocating

C. Centrifugal

D. Gear

271. The distribution of shear stress in a stream of fluid in a circular tube is_____________________?
comments icon0

A. Linear with radius for turbulent flow only

B. Linear with radius for laminar flow only

C. Linear with radius for both laminar & turbulent flow

D. Parabolic with radius for both laminar & turbulent flow

272. For a particle settling in water at its terminal settling velocity, which of the following is true ?
comments icon0

A. Drag = weight

B. Buoyancy = weight + drag

C. Drag = buoyancy + weight

D. Weight = buoyancy + drag
273. Centrifugal compressors compared to reciprocating compressors__________________?
comments icon0
A. All A., B. and C.

B. Have quieter operation

C. Require less space

D. Have lower operating costs

274. Mass velocity in case of steady flow and through a constant cross-section conduit is independent of the _________________?
comments icon0

A. Temperature

B. Pressure

C. Both A. & B.

D. Neither A. nor B.

275. 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.

276. The terminal velocity of a particle moving through a fluid varies as dp n. The value of n is equal to _______________ in Stokes law regime?
comments icon0

A. 1.5

B. 2

C. 0.5

D. 1

277. The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids ?
comments icon0

A. Having high viscosities

B. Moving at low velocities

C. Both A. & B.

D. Neither A. nor B.

278. With increase in the ratio of orifice diameter to pipe diameter in case of an orificemeter, the overall pressure loss_______________?
comments icon0

A. Increases linearly

B. Remain constant

C. Increases

D. Decreases

279. 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 N/H0.5

C. D = 1840 H/N

D. D = 1840 H0.5/N
280. Priming is needed in a ______________ pump?
comments icon0

A. Reciprocating

B. Gear

C. Diaphragm

D. Centrifugal
281. With increasing flow rate, the hydraulic efficiency of a centrifugal pump__________________?
comments icon0

A. Remains constant

B. Monotonically decreases

C. Decreases and then increases

D. Increases and then decreases

282. Non-colloidal solution is an example of the _______________ fluid?
comments icon0

A. Pseudo-plastic

B. Non-Newtonian

C. Newtonian

D. Dilatent

283. With increase in the shear rate, the apparent viscosity of pseudo-plastic fluids__________________?
comments icon0

A. May increase or decrease; depends on the magnitude of shear rate

B. Decreases

C. Remain same

D. Increases

284. Colebrook equation for friction factor in turbulent flow is given by, f-0.5 = -4 loge [(?/D) + (1.26/NRe ?F). It reduces to Nikuradse equation for a value of (?/D) equal to __________________?
comments icon0

A. 0

B. ?

C. 0.5

D. 1
285. Capillary rise of mercury in a small diameter tube is proportional to (where, d = diameter of the tube, ? = surface tension of mercury)____________________?
comments icon0

A. 1/?

B. d

C. ?

D. 1/d

286. A Rotameter works on the principle of _______________ pressure drop?
comments icon0
A. Constant

B. Variable

C. Both A. & B.

D. Neither A. nor B.

287. Which law is followed by the velocity distribution in the turbulent boundary layer ?
comments icon0
A. Logarithmic law

B. Linear law

C. None of these

D. Parabolic law

288. Bernoullis equation accounts for the_____________________?
comments icon0
A. Different forms of mechanical energy

B. Various masses

C. Various momentums

D. None of these

289. In turbulent flow, the__________________?
comments icon0

A. Momentum transfer is on molecular scale only

B. Shear stresses are generally larger than in a similar laminar flow

C. Shear stress is caused more effectively by cohesion than momentum transfer

D. Fluid particles move in an orderly manner

290. 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, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ?
comments icon0

A. 0.8

B. 0.5

C. 0.7

D. 0.2

291. 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. B is above G

C. G is above B

D. B & G coincide

292. The ratio of the depth of flow to the hydraulic radius for the most economical trapezoidal section, in open channel flow is_____________________?
comments icon0
A. 2

B. 1

C. 1.5

D. 0.5

293. In a stabilised soap bubble, pressure inside it compared to external pressure is________________?
comments icon0

A. Less

B. Same

C. Unpredictable

D. More
294. Which of the following is dimensionless ?
comments icon0
A. Fanning friction factor

B. Specific volume

C. None of these

D. Angular velocity

295. Boundary layer thickness in laminar flow over a flat plate increases as(where, d = distance from the leading edge.) ?
comments icon0

A. d2

B. d1/3

C. d2/3

D. ?d
296. Head developed by a centrifugal pump depends on its___________________?
comments icon0

A. Speed

B. Impeller diameter

C. Both A. and B.

D. Neither A. nor B.

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

A. None of these

B. Elevation & kinetic energy

C. Elevation & pressure

D. Kinetic energy & pressure

298. Which of the following has the maximum compression ratio ?
comments icon0

A. Blower

B. Vacuum pump

C. Compressor

D. Fan

299. In power law, ? = [A (du/dy)2 + B] then the fluid is__________________?
comments icon0

A. Rheopectic

B. Dilatant

C. Thixotropic

D. Newtonian
300. The line of action of the buoyant force acts through the____________________?
comments icon0

A. None of these

B. Centroid of the volume of any floating body

C. Centroid of the displaced volume of fluid

D. Centre of gravity of a submerged body