Chemical Engineering Mcqs

Which of the following options will facilitate the achievement of a very high head (say 30 metres) in case of a centrifugal pump ?

• (A)  Increasing the impeller speed and the volute area
• (B)  Increasing the number of vanes in the impeller
• (C)  Mounting of two or more impellers in series on a single shaft
• (D)  Either of

Answer

Submitted By :Ali Uppal

If in a flow field, between any two points, then the flow must be___________________?

• (A)  Steady, incompressible, irrotational
• (B)  Steady, compressible, irrotational
• (C)  Steady, compressible and along a streamline
• (D)  Unsteady, incompressible, irrotational

Answer

Submitted By :Ali Uppal

A gas (density = 1.5 kg/m3, viscosity = 2 × 10‒5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5 kg/m3and viscosity of 3 × 10‒5kg/m.s flowing at 3 m/s will be________________?

• (A)  8400 Pa/m
• (B)  12600 Pa/m
• (C)  18900 Pa/m
• (D)  16800 Pa/m

Answer

Submitted By :Ali Uppal

Cd is always ______________ Cc?

• (A)  Greater than
• (B)  Less than
• (C)  Equal to
• (D)  Either more or less than

Answer

Submitted By :Ali Uppal

Cavitation in a pump creates so many undesirable effects. Out of the following, which is not an undesirable effect created by cavitation ?

• (A)  Decrease in effect
• (B)  Increase in thrust
• (C)  Develops noise
• (D)  Develops high pressure

Answer

Submitted By :Ali Uppal

Maintenance cost of a ______________ pump for a particular duty is the least?

• (A)  Centrifugal
• (B)  Reciprocating
• (C)  Volute
• (D)  Gear

Answer

Submitted By :Ali Uppal

Water flow rate in a pipe of 3.5 metres diameter can be most economically and conveniently measured by a/an ________________?

• (A)  Pitot tube
• (B)  Venturimeter
• (C)  Orificemeter
• (D)  Rotameter

Answer

Submitted By :Ali Uppal

N. second/m2 is___________________?

• (A)  The S.I. unit of dynamic viscosity
• (B)  The S.I. unit of kinematic viscosity
• (C)  Equivalent to one poise
• (D)  Equivalent to one stoke

Answer

Submitted By :Ali Uppal

The dimension of surface tension is________________?

• (A)  ML-2
• (B)  MT-2
• (C)  MLT-2
• (D)  ML-2T

Answer

Submitted By :Ali Uppal

Friction factor for a hydraulically smooth pipe at NRe = 2100 is f1. If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe, will_______________?

• (A)  Increase
• (B)  Decrease
• (C)  Remain unchanged
• (D)  Increase or decrease depending on the pipe material

Answer

Submitted By :Ali Uppal