Chanakya on his way to home saw a farmer digging the soil. He observed that digging tool had an iron blade fixed to a wooden handle. He wondered how the iron blade gets fixed to a wooden handle even when the iron ring is smaller than a wooden handle. What do you think can be the way to do this?
On heating the iron ring, it expands and so it becomes bigger in size. The wooden handle can go into the bigger hole. When iron rim is cooled it contracts and fits the wooden handle tightly. This same principle is used in many applications where a snug fit is required in metallic parts.