Question

Three bodies $A$, $B$ and $C$ are in thermal equilibrium. The temperature of $B$ is ${45}^{o}C$, then the temperature of $C$ is ____________

• A. ${45}^{o}C$
• B. ${50}^{o}C$
• C. ${40}^{o}C$
• D. Any temperature

Answer 1

The correct option is A ${45}^{o}C$

According to zeroth law of thermodynamics if two thermodynamic system are in thermal equilibrium with a third them they are in thermal equilibrium with each other.

Accordingly thermal equilibrium between system is a transitive relation. So, If $A,B$ and $C$ are in thermal equilibrium $\&$ temperature of $B$ is $45°C$ then the $C$ will have same $45°C$ temperature.

Hence, the answer is $45°C.$