A. Over-sizes are present in undersize fraction
B. Under-sizes are retained in oversize fraction
C. Screen is plugged with solid particles
D. Screen capacity is abruptly increased
Related Mcqs:
- Higher is the mesh number, smaller will be the aperture size of the screen. It means that the aperture size of a 200 mesh screen will be smaller than that of 20 mesh screen. This is valid for__________________?
A. British standard screens
B. German standard screens (DIN 1171) etc
C. American standard screens (ASTM and Tyler standard screens)
D. All A., B. and C. - increasing the capacity of a screen _______________ the screen effectiveness?
A. Decreases
B. Increases
C. Does not effect
D. None of these - The ratio of the area of openings in one screen (Taylor series) to that of the openings in the next smaller screen is_________________?
A. 1.5
B. 1
C. √2
D. None of these - A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is_________________?
A. 0.50
B. 0.58
C. 0.68
D. 0.62 - Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of ____________ mm?
A. 0.007
B. 0.30
C. 50
D. 0.014 - Screen capacity is proportional to (where, S = screen aperture)____________________?
A. S
B. 1/S
C. S2
D. √S - Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with ______________ to get the same for dry grinding?
A. 1.0
B. 0.5
C. 1.34
D. 4.34 - 200 mesh screen means 200 openings per_____________________?
A. cm2
B. cm
C. inch
D. inch2 - Screen efficiency is______________________?
A. Recovery/rejection
B. Recovery
C. Rejection
D. None of these - Screen capacity is not a function of__________________?
A. Its openings size
B. Screening mechanism
C. Screening surface
D. Atmospheric humidity
