Question

Which of the following is an example of reversible process?

(a) Wood to ashes

(b) Burning of matchstick

(c) Making roti from wheat flour

(d) Frictionless to and fro motion

I had been asked this question by my college director while I was bunking the class.

This intriguing question comes from Thermodynamics in section Thermodynamics of Physics – Class 11

Answer 1

The correct option is (d) Frictionless to and fro motion

For explanation I would say: In frictionless to and fro motion, no form of energy is lost so the path followed from one point to another can be exactly retraced. While the other three are chemical changes and cannot be reversed.