​ If a steel rod is clamped between two walls such that it just fits into it and then heated , it would exert some force on the rod. But since no change in length takes place , can I say that the steer so produced is zero. If so then what about the hooks law? Plz answer soon.

The strain is produced . Strain is produced when there is change in length of rod from the normal length of the rod. In this case when you heated the rod the normal length of rod is not the original length of the rod but the length after the thermal expansion of the rod. Now the because of the wall this shrinked to its original length , so now the strain is the length to which the rod tried to increase but couldn’t

What happens exactly is that in actual` the moisture in our skin gets cooled and thus gets freezed by the ice . This occurs only if it is cooler than our body . Ice us most cold when just taken out so it is easily stucks our fingers. Later , as its tenperature decrease ralative to our body then it cannot stick any more