Asquare is cut out of a copper sheet. a circular hole is drilled in the square. the square is heateduniformly. as a result, the diameter of the hole
increases
decreases
stays the same
the answer depends on the size of the hole.

diameter of the hole   increases .

Explanation:

In this case , the square sheet with hole  will expand as if  it had no hole .

A hollow sphere will expand to the same extent that a solid sphere expands .If we assume no hole in the square sheet of copper , the distance between two extreme point on the diameter will increase . It will increase even if circular hole is present . Hence diameter of the hole will increase.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.