Observe the given diagram and answer the question that follows. Which effect of electricity is used?

Here, the heating effect of electric current is used. When current passes through the heating element, it gets heated. That heat is used for ironing the clothes.

Observe the given diagram and answer the question that follows. How is the temperature adjusted when we rotate the knob while using an electric iron on different fabrics?

An electric iron generally uses a bimetallic strip which bends when temperature increases. This bimetallic strip is connected to a contact spring through small pins. It will open the electric circuit and stops further heating. It works like a bridge to connect or disconnect the circuit to regulate the heating while adjusting the knob according to the fabric requirements.

Observe the given diagram and answer the question that follows. What will happen if the brass layer and iron layer is interchanged in their placement in the bimetallic strip?

A bimetallic thermostat device consists of a strip of two different metals having different coefficients of linear expansion. Brass has a linear expansion more than iron. If the brass layer and iron side is interchanged it will bend in the opposite direction which will not help the circuit to break at required temperature.