Question

i. When long steel bridges are built, one end is fixed and the
other rests on rollers
ii. Small gaps are often left between sections of concrete roads or
overbridges when they are constructed. You may have noticed
these as tiny 'bumps' when you ride in a car over such gaps.
iii. Electric cables when fixed between poles are allowed to sag EXPLAIN THESE ​

Answer 1

Answer:

This is due to the vibrations caused while the vechiles moves on it. The gaps prevents the bridge to break.