Question

In superficial expansion of solids

• A. Increase in thickness is negligible as compared to increase in length and breadth
• B. Increase in length and breadth is negligible as compared to increase in thickness
• C. Both
• D. None

Answer 1

Answer: (A)

Increase in thickness is negligible as compared to increase in length and breadth

On heating a thin plate(lamina),the increase in its thickness is negligible as compared to the increase in length and breadth.
Thus,for a plate or lamina,we consider the expansion in its area which is called the superficial/surface expansion.