Question

Railway tracks are constructed with gaps in the rails to allow the metal rails to ________ due to the heat of summer and the heat generated by ________.

Answer 1

1. The small gaps, that are left between the section of the rail form each side of the parallel railways over which railway engines, coaches, trains, and trams run.
2. These gaps which are of the order of a few millimeters are provided to allow room for the rails to expand the rise in temperature due to the atmospheric temperature as well as the friction caused by the running of the train.
3. All materials expand when heated and contract when cooled.
4. The extent of expansion and contraction is quite low to be noticed by people or makes much difference in most situations.
5. However, since each section of the rail is very long, the expansion due to heating is significant, and unless space is provided for the expansion of rails, the rails will bend to accommodate the increased length.
6. This will make the railway unfit for running of trains.

Hence, the railway tracks are constructed with gaps in the rails to allow the metal rails to allow expansion of rails due to the heat of summer and the heat generated by the running of trains.