Question

Why does the heat of the heating element stop when the desired temperature in an electric iron is reached?

a. the thermostat blade opens electrical contacts.
b. the circuit through the element is closed.
c. the switch bypasses the thermostat.
d. the contacts on the blade touch.

Answer 1

The heat stops because the thermostat blade open the electrical contacts and current is cut off.

Answer 2

The heat of the heating element stops when the desired temperature in an electric iron is reached because A. the thermostat blade opens electrical contacts.
This is why heating ceases to rise or fall (it stops completely) once the thermostat's blade opens.