Engineering Questions with Answers - Multiple Choice Questions
Mechanical Operations MCQ’s – Flow of Filtrate Through Cloth and Cake
1 - Question
What does the following represents?
a) Fourier’s law
b) Kick’s law
c) Newton’s law
d) Radiation law
View Answer
Answer: b
Explanation: Where, the rate of transport of mass, dm/dt across an interface of area A is proportional to the concentration gradient, dc/dx, across the interface.
2 - Question
As the particle size increases, flow properties also ___
a) Increase
b) Decrease
c) Remain same
d) Constant
View Answer
Answer: a
Explanation: As the particle size increases, flow properties also increases due to the influence of gravitational force on the size.
3 - Question
In a ______ the material present in the containers is agitated either by an oscillatory motion.
a) Propeller mixer
b) Shaker mixer
c) Impellor mixer
d) Turbine mixer
View Answer
Answer: b
Explanation: In these mixers, the material present in the containers is agitated either by an oscillatory for small scale mixing or by a rotary movement large scale mixing.
Explanation: In these mixers, the material present in the containers is agitated either by an oscillatory for small scale mixing or by a rotary movement large scale mixing.
4 - Question
_____ may be used for mixing relatively low viscosity dispersions.
a) Propeller mixer
b) Shaker mixer
c) Impellor mixer
d) Motor mixer
View Answer
Answer: a
Explanation: They are comprising a rotating shaft with propeller blades attached, used for mixing relatively low viscosity dispersions (thicker solutions) and maintaining contents in suspension.
5 - Question
At what speed does the propeller mixer rotates?
a) 8000 rpm
b) 7000 rpm
c) 5000 rpm
d) 1000 rpm
View Answer
Answer: a
Explanation: It rotates at a very high speed i.e. up to 8000 r.p.m. due to which mixing is done in a short time, they are much smaller in diameter than paddle and turbine mixers.
6 - Question
What viscosity propellers can handle?
a) 2.0 pa.s
b) 1.5 pa.s
c) 5 pa.s
d) 8 pa.s
View Answer
Answer: a
Explanation: Propellers are used when high mixing capacity is needed. These are effective in handling liquids having a viscosity of about 2.0 Pascal second.
7 - Question
What are the power requirements of a radial impellor?
a) 50 to 100 hp
b) 1 to 1000 hp
c) 2 to 500 hp
d) 500 to 2000 hp
View Answer
Answer: b
Explanation: Power may range from 1 to 1000 hp, the impellor speed is typically between 50 and 150 rpm but it may be as high as 400 rpm.
8 - Question
The tank diameter to liquid ratio usually is ____
a) 1:1
b) 1:2
c) 2:3
d) 3:4
View Answer
Answer: a
Explanation: Equipment’s such as shaker mixers, propeller mixers, these equipment’s contain a flat bottomed with tank diameter to liquid ratio usually as 1:1.
9 - Question
For an impellor, Shearing action is very good at high speed.
a) True
b) False
View Answer
Answer: a
Explanation: It circulates by axial parallel flow to the shaft and its flow pattern is modified by the baffles, which also can cause shearing action at high speeds.
10 - Question
What power requirement’s does an axial impellor requires?
a) = 5 hp
b) > 2 hp
c) < 5 hp
d) > 5 hp
View Answer
Answer: d
Explanation: When a high axial circulation rate is desired, the power consumption is more than 5 horse power.