Question

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:

• A. A is true but R is false
• B. Both A and R are true and R is the correct explanation of A
• C. Both A and R are true but R is NOT the correct explanation of A
• D. A is false but R is true

Answer 1

The correct option is C

Both A and R are true but R is NOT the correct explanation of A

If a rod is heated, then the linear dimension of the rod gets increased due to the property of the rod. If the rod is free from any restriction, then there will be no stress. The rod will expand due to the increase in the temperature.

Therefore, both A and R are true.

Hence, the correct option is $\left(C\right)$