Question

Unit operation is based on ______________

(a) law of conservation of mass only

(b) law of conservation of energy  only

(c) law of conservation of mass and energy

(d) third law of thermodynamics only

This question was addressed to me by my school principal while I was bunking the class.

I need to ask this question from Basic Principles of Food Process Engineering topic in section Introduction & Unit Systems of Food Processing Unit Operations

Answer 1

The correct option is (c) law of conservation of mass and energy

For explanation: Law of conservation of mass applies to each component entering the process. For example, amount of milk entering through pasteurization inlet should be equal to amount of milk leaving the pasteurization outlet. Similarly, law of conservation of energy applies where total energy in the material entering the process plus energy added in the process must be equal to total energy leaving the process.