1. The problem asks to define three types of thermodynamic changes and list five thermometers. 2. Definitions: (i) Isobaric process: A thermodynamic process that occurs at constant pressure. The pressure $P$ remains unchanged during the process. (ii) Isothermal process: A thermodynamic process that occurs at constant temperature. The temperature $T$ remains constant throughout the process. (iii) Adiabatic process: A thermodynamic process where no heat is exchanged with the surroundings. The system is thermally insulated, so $Q=0$. 3. Explanation: - In an isobaric process, volume or temperature may change but pressure stays fixed. - In an isothermal process, the internal energy remains constant because temperature is constant. - In an adiabatic process, changes in pressure, volume, and temperature occur without heat transfer. 4. Five common thermometers: - Mercury thermometer - Alcohol thermometer - Digital thermometer - Infrared thermometer - Thermocouple thermometer This completes the definitions and listing as requested.