Final answer:
The most common form of switching used for mechanical thermostats is mechanical switching. It utilizes physical movements caused by changes in temperature-sensitive materials to control the electrical circuit and regulate temperature.
Step-by-step explanation:
The most common form of switching used for mechanical thermostats (t-stats) is mechanical switching. Mechanical thermostats typically use bi-metallic strips or gas-filled bellows as sensors. The interaction between the sensor and a set temperature causes physical movement, which in turn mechanically opens or closes an electrical circuit to start or stop the flow of electricity to the heating or cooling system.
Mechanical switching is reliable and has been used confidently for many years in a variety of environments. It does not require external power sources like electronic components do and can operate in more demanding conditions. However, mechanical thermostats do not offer the same level of precision that electronic thermostats can provide.