Mixing MCQs : This section focuses on the "Mixing". These Multiple Choice Questions (MCQs) should be practiced to improve the Mixing skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
Mixing Index is a ratio of the standard deviation of various products during mixing to that at zero mixing.
A. TRUE
B. FALSE
Question 2
Mixing index is applicable for mixing of solids at zero time.
A. TRUE
B. FALSE
Question 3
Power required for a gassed system is more than that required for an ungassed system.
A. TRUE
B. FALSE
Question 4
Rate of mixing at any time is given by the extent of mixing at that particular time.
A. TRUE
B. FALSE
Question 5
The clearance between the impeller and the vessel in a mixer is usually kept _____
A. High
B. Low
C. Cannot be determined
D. None of the mentioned
Question 6
The force used for mixing by mixing equipment for pastes and dough is _____
A. Centrifugal smearing
B. Impact
C. Tumbling
D. All of the mentioned
Question 7
Which of the following conditions show that a certain industrial mixer is the best?
A. Power load for mixing is minimum
B. Standard deviation is minimum
C. Time required for mixing is minimum
D. All of the mentioned
Question 8
Which of the following does NOT include power required for mixing by an impeller?
A. Rheological nature of the fluid
B. Friction in the motor
C. Speed, nature and type of the impeller
D. None of the mentioned
Question 9
Which of the following is NOT a mixing involved with fluids in the food industry?
A. Soup powders
B. Carbonated drinks
C. Oxygen transfer in fermentation broths
D. None of the mentioned
Question 10
Which of the following is NOT an application of mixing solids in the food industry?
A. Biscuit/bakery making
B. Poultry and cattle feed
C. Chips and snacks industry
D. None of the mentioned
Question 11
Which of the following is true with respect to Carbonation?
A. Gas-liquid mixing
B. Helps improve storage life
C. Increased pressure
D. All of the mentioned
Question 12
Which of the following is true with respect to mixing operations in the food industry?
A. Ice creams
B. Confectionery products
C. Chlorinated waters
D. All of the mentioned
Question 13
Which of the following with respect to mixing is true?
A. It is used to distribute heat uniformly to all the components of the mixture
B. Mixing becomes difficult when one of the phases to be mixed is in minor quantity
C. Solid-solid mixing is more difficult than other phases
D. All of the mentioned
Question 14
With respect to dipping oil emulsions, which of the following is true?
A. Used for easy dehydration of food
B. Gives a thin layer of coating on the fruit berries
C. Dipping oil made from an emulsion by mixing of fatty esters with some amount of aqueous potassium carbonate solutions by high speed impellers
D. All of the mentioned
Question 15
With respect to the relationship between the power number and the impeller Reynolds's number, which amongst the following statements is true?
A. In the turbulent region, the NRe,i has no impact over NPo
B. In the transient region, the NRe,i has no impact over NPo
C. In the laminar region, the NPo continually falls as NRe,i increases
D. None of the mentioned
Question 16
“Pitch of a propeller”, Here what does pitch refer to?
A. Advance per resolution
B. Advance per rotation
C. Advance per Sharpness
D. Advance per revolution
Question 17
“Rotational stirrers are advantageous for mixing”?
A. TRUE
B. FALSE
Question 18
Are Propellers and Impellers different in function from each other?
A. TRUE
B. FALSE
Question 19
Mixing is sufficiently done away from the impeller?
A. TRUE
B. FALSE
Question 20
What is the ratio of tank diameter to impeller diameter for Newtonian fluids?
A. 3:1
B. 2:1
C. 1:3
D. 1:2
Question 21
What is the width of baffle in order of the tank diameter used for mixing?
A. 1/5- 1/10
B. 1/12-1/15
C. 1/10-1/12
D. 1/5-1/12
Question 22
Which is the most frequently used impeller in the fermentation industry regarded as 6- flat-blade disc-mounted turbine?
A. Propeller turbine
B. Rushton turbine
C. Bladeless turbine
D. Screw turbine
Question 23
Which of the following is the slowest step in mixing process?
A. Distribution
B. Diffusion
C. Dispersion
D. Decomposition
Question 24
Which type of fermenter is used mainly for mixing?
A. Air-Lift fermenter
B. Stirred Tank fermenter
C. Fluidised Bed bioreactor
D. Packed Bed bioreactor