The zeroth law says two systems in equilibrium with a third are:
- In equilibrium
- In excitation
- In expansion
- In extension
Show answer and solution
Correct answer: A. In equilibrium
1. The third system acts as a reference.
2. This gives the concept of temperature.
3. They are in thermal equilibrium with each other.
_Source: syllabus Physics, Ch 11 'Thermodynamics'_