Question

Which of the cases is suitable for concentration by hand picking?

(a) When either the ore or the impurities are magnetic

(b) When the ore particles are heavier than the impurities

(c) When the ores are good conductors of electricity

(d) When the impurities can be distinguished from the ore by the naked eye

I got this question in an interview for internship.

The above asked question is from Concentration of Ores in chapter General Principles and Processes of Isolation of Elements of Chemistry – Class 12

Answer 1

Right choice is (d) When the impurities can be distinguished from the ore by the naked eye

The explanation is: In the case of concentration by hand picking, it is necessary that the impurities be easily distinguishable from the particles of the ore. Only if these impurities can be distinguished by the naked eye, is the ore said to be suitable for concentration by hand picking.