Question

Why is one end of the beams of steel bridge kept on a roller instead of fixing in a pillar.

Answer 1

The reason behind keeping one end of the beams of steel bridge on a roller instead of fixing in a pillar.

1. Thermal expansion occurs in steel bridge in summers.
2. Because of this the roller can move ahead if there is any expansion.
3. Therefore one end of the steel bridge is kept on roller.

Thus, the thermal expansion is the reason behind keeping one end of the beams of steal bridge on a roller instead of fixing in a pillar.