The sagging of overhead electrical wires is caused by
A
radiation of heat.
B
rough handling.
C
gravitational attraction
D
Linear expansion
Verified Correct Answer: D.
Physical Principles & Numerical Solution
The sagging of overhead electrical wires is caused by linear expansion.
Linear expansion is the tendency of materials to expand in length when they are heated. When overhead electrical wires are heated by the sun, they expand and sag.
Source: Myschool Past Questions Archive (Record #69410)