Separation of isotopes is generally done using a/an _______________ centrifuge?
A. Ultra
B. Disk-bowl
C. Both A. & B.
D. Neither A. nor B.
Mechanical Operations
Grinding efficiency of a ball mill is of the order of _______________ percent?
Grinding efficiency of a ball mill is of the order of _______________ percent?
A. 1-5
B. 40-50
C. 75-80
D. 90-95
Cement clinker is reduced to fine size by a _____________________?
Cement clinker is reduced to fine size by a _____________________?
A. Roll crusher
B. Ball mill
C. Tube mill
D. Hammer mill
In screen analysis, the notation +5 mm/-10 mm means particles passing through ____________________?
In screen analysis, the notation +5 mm/-10 mm means particles passing through ____________________?
A. 10 mm screen and retained on 5 mm screen
B. 5 mm screen and retained on 10 mm screen
C. Both 5 mm and 10 mm screens
D. Neither 5 mm nor 10 mm screen
The critical speed of a trommel (N) is related to its dia D. as _____________________?
The critical speed of a trommel (N) is related to its dia D. as _____________________?
A. N ∝ 1/√D
B. N ∝ √D
C. N ∝ D
D. N ∝ 1/D
At low Reynold’s number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied: Po = ρ/ρN3 D5: Power number Re = ρ N D2/μ: Reynold’s number N is the impeller rotational speed, and D is the impeller diameter ?
At low Reynold’s number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied: Po = ρ/ρN3 D5: Power number Re = ρ N D2/μ: Reynold’s number N is the impeller rotational speed, and D is the impeller diameter ?
A. Po ∝ Re-1.0
B. Po ∝ Re0.0
C. Po ∝ Re0.5
D. Po ∝ Re1.0
A _______________ employs a set of screen across a flow channel for the separation of dirt/rust from a flowing liquid stream?
A _______________ employs a set of screen across a flow channel for the separation of dirt/rust from a flowing liquid stream?
A. Thickener
B. Classifier
C. Strainer
D. Clarifier
Laminar flow region is said to exist during agitation of a liquid in an agitator, when the value of Reynolds number is________________?
Laminar flow region is said to exist during agitation of a liquid in an agitator, when the value of Reynolds number is________________?
A. > 10
B. < 10
C. > 100
D. < 100
_______________ centrifuge is the most suitable for separation of non-friable crystals?
_______________ centrifuge is the most suitable for separation of non-friable crystals?
A. Tubular bowl
B. Disc-bowl
C. Perforated horizontal basket continuous
D. Suspended batch basket
In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the ________________ crushing?
In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the ________________ crushing?
A. Secondary
B. Fine
C. Primary
D. Ultrafine