Answer:
Applications of zeroth law of thermodynamics:
1. When we get very hot food, we wait to make it normal. In this case, hot food exchanges heat with surrounding and brings equilibrium.
2. We keep things in the fridge and those things come equilibrium with fridge temperature.
3. Temperature measurement with a thermometer or another device.
4. In the HVAC system, sensors or thermostats are used to indicate temperature. It always comes in a thermal equilibrium with room temperature.
5. If you and the swimming pool you’re in are at the same temperature, no heat is flowing from you to it or from it to you (although the possibility is there). You’re in thermal equilibrium.