WHY BLOCK HOLE BECOMES SMALL ON HEATING ?

PROFESSOR ABDUL GAFAR MEMON TEACHING PHYSICS

 QUESTION BY STUDENT AND ANSWER .

STUDENT : SIR WHWN A BLOCK WITH A HOLE IN IT IS HEATED , WHY DOES NOT THE MATERIAL AROUND THE HOLE EXPANDS INTI THE HOLE AND MAKE IT SMALL ?

SIR : WELL BETA THERMAL EXPANSION OF  HOMOGENEOUS  SUBSTANCES CAUSES INCREASE IN ALL DIRECTION WITH LINEAR THERMAL EXPANSION COEFFICIENT. AS SHOWN IN BELOW PICTURE

PICTURE DESCRIBING THE EXPANSION IN ALL DIRECTION 

 THE INCREASE IN ALL DIRECTION CAUSES AN EFFECTIVE MAGNIFICATION OF AN OBJECT. SO HOLE IN THE BLOCK ,  ON HEATING ,EXPANDS UPWARD.
(I.E BECOMES BIG).

do an experiment on your own

SHOWING LINEAR THERMAL EFFECT ON HOLE.