यदि किसी पदार्थ का रेखीय प्रसार गुणांक (coefficient of linear expansion) 2 × 10-5 °C-1 है, तो इसका क्या अर्थ है?

Small gaps are deliberately left between consecutive steel rails on a railway track to:

Given below are two statements, one labeled as Assertion (A) and the other as Reason (R). Select the correct answer from the options below. Assertion (A): A very hot glass cracks when cold water is poured onto it. Reason (R): Glass expands when heated and contracts when cooled.