The video tutorial explains the automatic on-off function of electric irons, which is controlled by a thermostat. It highlights the difference between a thermostat and a thermometer, emphasizing that a thermostat regulates temperature while a thermometer measures it. The tutorial details how an iron heats up using a coil and the role of a thermostat in preventing overheating. It further explains the function of a bimetallic strip in the thermostat, which bends to break the circuit when the temperature exceeds a certain limit, thus regulating the iron's temperature and ensuring safety.

What is the primary function of a thermostat in an electric iron?

• To measure the temperature

• To regulate the temperature

• To increase the temperature

• To decrease the temperature

Why is it important for an iron to have a thermostat?

• To make the iron lighter

• To make the iron heavier

• To prevent the iron from overheating

• To make the iron consume more electricity

How does a bimetallic strip in a thermostat function?

• By melting at high temperatures

• By expanding and contracting to open or close a circuit

• By changing color with temperature

• By vibrating to produce heat

What happens when the bimetallic strip bends in a thermostat?

• The circuit remains closed

• The circuit opens and stops the current

• The iron heats up more

• The iron cools down immediately

What causes the bimetallic strip to bend in a thermostat?

• The presence of a gas

• The presence of a liquid

• The difference in expansion rates of two metals

• The presence of a magnetic field