Multiple choice

Glass when heated cracks because

  1. glass is a bad conductor of heat

  2. it is brittle

  3. on heating it expands unevenly

  4. None of the above

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Glass is a poor conductor of heat. When heated, the part in contact with the heat source expands, while the rest of the glass remains cool and does not expand, creating internal stress that causes the glass to crack.