Subject :NSO Class : Class 7
On a cold day, it is hard to open the metallic lid of a tight glass container. But when you gently heat the neck you can easily open the lid. Why?
AOn heating, glass expands and lid contracts.
BOn heating, lid expands more than the neck and
thus slides easily.
CNeck becomes slippery on heating.
DLid of the bottle cannot bear the heat.
Ans 1:
Class : Class 8
B) On heating ,lid expands more than the neck and thus slides easily.