Project ForgeFluid Mechanics
Mechanical Operations
GATE 2015
Hard
Sand particle diameters range from 50 to 150 microns; the number of particles of diameter x is proportional to 1/(50+x). The average diameter (microns), rounded to 1 decimal place, is
94.3 microns(± 1 accepted)
Explanation
Avg=∫50^150 x/(50+x)dx / ∫50^150 1/(50+x)dx = [100−50ln2]/ln2 = 65.34/0.693=94.3 microns.
Source: GATE CH 2015 (2015)
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