20. A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will A.Increase B.Decrease C.Remain unaffected D.Have its shape changed
Option A Solution: The metal ball can be considered to be made up of several layers of thinner ones. On heating each of these layers will increase in radius. As the inner most layer also increases its radius, the volume inside it i.e, the volume of the hollow portion will also increase.
