Thermometry & Thermal Expansion
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:
Show answer and solution
Answer: (c)
- A free rod can expand without restriction, so no thermal stress develops: A is true.
- On heating the length increases: R is true.
- Stress arises only when expansion is prevented; the mere increase in length does not explain the absence of stress.
- So the answer is (c) both true, R not the correct explanation.