Question

A piece of glass is heated to a high temperature and then allowed to cool. If it cracks, a probable reason for this is the following property of glass :

• A. Low thermal conductivity
• B. High thermal conductivity
• C. High specific heat
• D. High melting point

Answer 1

The correct option is A Low thermal conductivity

In case of low thermal conductivity, the heat is not distributed properly. When it is heated, the temperature at its outer surface increases more than in the inner part. This means expansion on the outer part will be more than the inner part. So a stress will be generated. If the body is cooled again, the outer surface will contract more rapidly, then the inner part. This stress will generate crack in the body.