Final answer:
In electronic thermostats, electrical switching is primarily done by solid-state components, which are more prevalent in modern electronic designs compared to mechanical contacts, mercury switches, or magnetic relays.
Step-by-step explanation:
The electrical switching in an electronic thermostat (t-stat) is often done by solid-state components such as transistors and integrated circuits. These components are used in modern electronic devices to control the functions of the device, including managing temperature settings in heating, ventilation, and air conditioning (HVAC) systems.
In contrast, mechanical contacts and mercury switches were used in older thermostats, but they are less common in newer designs due to concerns about durability and environmental implications of mercury. Magnetic relays can still be found in some systems, particularly where isolation is a concern or higher power needs to be switched, but solid-state is more prevalent in compact and lightweight designs.