Size Analysis - Mechanical Operations - GATE Questions

GATE-CH-1989-3-i-b-mo-1mark

1989-3-i-b-mo

Weight mean diameter is given by:

\(\displaystyle \frac {\sum n_i d_i^4}{\sum n_i d_i^3}\)
\(\displaystyle \left (\frac {\sum n_i d_i^3}{\sum n_i}\right )^{1/3}\)
\(\displaystyle \frac {\sum n_i d_i^3}{\sum n_i d_i^2}\)
\(\displaystyle \frac {\sum n_i d_i^2}{\sum n_i d_i}\)

GATE-CH-1996-1-6-mo-1mark

1996-1-6-mo

The distribution given by microscopic analysis of powder is

Number
Length
Area
Volume

GATE-CH-2002-1-16-mo-1mark

2002-1-16-mo

If \(d_p\) is the equivalent diameter of a non-spherical particle, \(v_p\) its volume and \(s_p\) its surface area, then its sphericity \(\phi _s\) is defined by

\(\phi _s = 6v_p/d_ps_p\)
\(\phi _s = v_p/d_ps_p\)
\(\phi _s = 6d_ps_p/v_p\)
\(\phi _s = d_ps_p/v_p\)

GATE-CH-2007-11-mo-1mark

2007-11-mo

In Tyler series, the ratio of the aperture size of a screen to that of the next smaller screen is

\(1/\sqrt {2}\)
\(\sqrt {2}\)
1.5
2

GATE-CH-2013-14-mo-1mark

2013-14-mo

In the Tyler standard screen scale series, when the mesh number increases from 3 mesh to 10 mesh, then

the clear opening decreases
the clear opening increases
the clear opening is unchanged
the wire diameter increases

GATE-CH-MT-2017-8-mo-1mark

MT-2017-8-mo

The size analysis of a ground quartz particles is given in the table below:

Size (mm)	Mass fraction of ground product retained on each sieve
4.76	0
3.36	0.2
2.38	0.4
1.68	0.3
1.19	0.08
< 1.19	0.02

The cumulative mass fraction of particles of size less than 1.68 mm is ____________

Answer

GATE-CH-1996-2-6-mo-2mark

1996-2-6-mo

The sphericity of a cylinder of 1 cm diameter and length 3 cm is

0.9
0.78
0.6
0.5

GATE-CH-2000-2-7-mo-2mark

2000-2-7-mo

The sphericity of a solid particle of cubical shape is

\(\pi \)
(\(\pi /6)^{1/3}\)
(\(\pi /6)^{1/2}\)
\(\pi /3\)

GATE-CH-2002-2-21-mo-2mark

2002-2-21-mo

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

0.50
0.58
0.68
0.62

GATE-CH-1995-7-mo-5mark

1995-7-mo

Calculate the surface-volume mean diameter (in \(\mu \)m) for the following particulate material. Show detailed calculations.

Size range, \(\mu\)m	Mass of particles in the range, g
\(-704+352\)	25
\(-352+176\)	37.5
\(-176+88\)	62.5
\(-88+44\)	75
Pan	50

Answer

GATE-CH-2017-38-mo-2mark

2017-38-mo

Size analysis was carried out on a sample of gravel. The data for mass fraction (\(x_i\)) and average particle diameter (\(D_{pi}\)) of the fraction is given in the table below:

\(x_i\)	\(D_{pi} \text {(mm)} \)
0.2	5
0.4	10
0.4	20

The mass mean diameter of the sample, to the nearest integer, is ____________mm.

Answer