Unit Operations

Question 1
Marks : +2 | -2
Pass Ratio : 100%
A jaw crusher uses _____
Compression
Shear
Cutting
None of the mentioned
Explanation:
A jaw crusher uses Compression.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
In deep freezers, the walls absorb heat from food materials by _____ and keep them cool.
Conduction
Convection
Radiation
None of the mentioned
Explanation:
In deep freezers, the walls absorb heat from food materials by radiation and keep them cool.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
When there is a mixture of liquids present, the boiling point lies between the boiling points of both the components.
True
False
Explanation:
When there is a mixture of liquids present, the boiling point lies between the boiling points of both the components.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Sedimentation and centrifugation involve two miscible phases.
True
False
Explanation:
Sedimentation and centrifugation involve two immiscible phases.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which of the following reason does NOT affect radiation between two parallel bodies?
Angle of vision
Orientation of surfaces
Emissivity of both
Smoothness and roughness
Explanation:
The angle of vision does not affect radiation between two parallel bodies. But, it is an important factor when it comes to curved surfaces.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: α=k/(ρCp)
True, False
True, True
False, False
False, True
Explanation:
α=k/(ρCp). α stands for thermal diffusivity.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: Generally, in small scaled jacketed pans, food products like jams, sauces etc are made.
True, False
True, True
False, False
False, True
Explanation:
Generally, in small scaled jacketed pans, food products like jams, sauces etc are made. Baffles provide structural support to tubes and prevent channeling also.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Фv is generally taken as 1 in food processing as generally very high wall temperatures aren’t reached and hence (µ/µw) * 0.14 is 1 as there isn’t much difference in µ and µw.
True
False
Explanation:
фv is generally taken as 1 in food processing as generally very high wall temperatures aren’t reached and hence (µ/µw) * 0.14 is 1 as there isn’t much difference in µ and µw.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: In the transient zone, the power input depends on the density and viscosity of the fluid.
True, False
True, True
False, False
False, True
Explanation:
In the laminar zone, the power input depends on the viscosity only. It is independent of the density of the fluid.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Statement 1: The radius of neutral zone depends on the radius of the centrifuge.
True, False
True, True
False, False
False, True
Explanation:
The radius of neutral zone depends on the radius of the centrifuge. More is the radius, more is the zone of centrifuge as it depends on the difference of the radii of the heavy and light zones.