Question

why the telephone wires which sag in summer become straight in winter???

Answer 1

The telephone wires which sag in summer become straight in winter ... During summer, the wires heat up and expand in length. Hence it sags down. During winter, the temperature drops and wires cool down. Due to decrease in temperature,it contracts in length and hence becomes straight.

Answer 2

less the temperature more is the contraction of that substance.....