*1. Grills of doors and windows are always painted before they are used.

Q.III Give scientific reasons :
*1. Grills of doors and windows are always painted before they are used.

Ans. 1.

Railings, iron bridges, grills of doors and windows, railway coaches, steel furniture, and bodies of truck, cars, buses are made of iron.

2. To protect them from rusting, a coating of paint is applied. By doing this, air and moisture cannot come in contact with the iron object and hence rusting doesn’t takes place.

So, grills of doors and windows are always painted before they are used.