Chemical Engineering - Mechanical Operations

Exercise :: Mechanical Operations - Section 1
21.
The distribution given by microscopic analysis of powder is

Answer: Option A

Explanation:

22.
Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, V_{p} = volume of one particle, ρ= density of particles)

A.
m /ρ . V_{p} B.
m . ρ/V_{p} C.
m . V_{p} /ρD.
V_{p} /m . ρ

Answer: Option A

Explanation:

23.
For a non-spherical particle, the sphericity

A.
is defined as the ratio of surface area of a sphere having the same volume as the particle to the actual surface area of the particle. B.
has the dimension of length. C.
is always less than 1. D.
is the ratio of volume of a sphere having the same surface area as the particle to the actual volume of the particle.

Answer: Option A

Explanation:

24.
In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is

Answer: Option B

Explanation:

25.
Ball mills and tube mills with flint or porcelain balls are used for size reduction of

A.
asbestos B.
rubber C.
non-metallic ores D.
limestone

Answer: Option C

Explanation: