JEE Main 2021 · 25 February · morning · Single correct · +4 / −1

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : When a rod lying freely is heated, no thermal stress is developed in it.
Reason R : On heating, the length of the rod increases.
In the light of the above statements, choose the correct answer from the options given below :

1. (a) A is true but R is false
2. (b) A is false but R is true
3. (c) Both A and B are true but R is NOT the correct explanation of A
4. (d) Both A and R are true and R is the correct explanation of A