Assertion: The zeroth law said that , when two systems A and B, are in thermal equilibrium, there must be a physical quantitiy that has the same value for both.
Reason : The physical quantity which is same for both system is temperature.

Options

A. If both assetion and reason are true and reaasons is the correct expanation of assetion
B. If both assetion and reason are tur but reason is not the correct explanation of assetion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Answer

A

Explanation

If A and B are separately in equilibrium with `C,T_(A)=t_(B) and T_(B)=t_(C)` .It means `t_(A)=t_(B)`i.e the systems A and B are also in thermal equilibrium.