Question

Which of the following methods can be used to produce nano-powders of oxides?

(a) Plasma arching

(b) Sol-gel technique

(c) Chemical vapour deposition

(d) Mechanical crushing

This question was addressed to me in an interview for job.

Question is taken from Nano Phase Materials topic in section Advanced Engineering Materials of Engineering Physics II

Answer 1

The correct answer is (c) Chemical vapour deposition

Best explanation: Chemical vapour deposition is used to prepare nano-powder. In this technique, initially, the material is heated to form a gas i=and is allowed to deposit on a solid surface under vacuum condition, which forms nano-powders on the surface of the solid.