Question

Give reason:

Telephone and electric wires placed overhead are always left a bit loose.

Answer 1

The reasons are:

1. Solids exhibit thermal expansion on heating and contraction on cooling down.
2. The same is observed in solids as they expand and contract during the summer and winter seasons respectively.
3. If these wires are put up during summer, they are let a bit loose to avoid the breakage due to contraction during winter.

Hence, the telephone and electric wires placed overhead are always left a bit loose.