In this chapter, heat is defined, zeroth law of thermodynamics is given, and temparature measurement with mercury thermomters, resistance thermometer, and constant volume gas thermometer are discussed.
* The energy that is tranferred from one body to the other, without any mechanical * work involved, is called heat.
* Zeroth law of thermodynamics: If two bodies A and B are in thermal equilibiurm and A and C are also in thermal equilibrium then B and C are also in thermal equilibrium.
* zeroth law allows us to introduce the concept of temperature to measure the hotness or coldness of a body.
* To measure temperature, we can choose a substance and look for a measurable property of the substance which monotonically changes with temperature.
* Length of mercury in long capillary, resistance of a wire, pressure of gas when volume is kept constant are properties which can be used for temperature measurement.