Question

Railway tracks have gaps between them to deal with expansion in:
A. hot days
B. cold days
C. winters
D. summers

Answer 1

Solids contract and expand due to the temperature changes in the environment. Keeping this fact in mind the railway tracks are made accordingly. Though the change in the size is small but it's really important to have spaces in between to prevent tragedies.

Complete step by step answer:
The property of expanding and contracting is very normal in solids that takes place due to the temperature changes in the environment. That’s why the railway tracks have gaps in between them to deal with the expansion.
The gaps in railway tracks make the railway tracks work without the interference when they undergo expansion due to the raised temperature. Gaps provide the spaces to the tracks to expand in summer heat easily and then again contract as the temperature drops down. Due to these gaps this would have been possible.
Now, what happens if there would have been no gaps? If there were no gaps then the rails would expand and have no space for expansion. They would simply force themselves to buckle thus making the track unserviceable. Even when the temperature drops down, they would have been so disturbed that proper alignment would not have been possible for the tracks.
Alternative for gaps is to cut the two adjoining rails in the form of an overlapping mortise joint, so that there is a significant overlap between the start of one rail and at the end of the other rail. This overlap area is allowed to slide thus absorbing any rail expansion.
If there would have been no such gaps available then the tracks would undergo a change in alignment causing the rail to derail. Hence, can cause tragedy.
The changes in the rail tracks occur in the hot days

So, the correct answer is Option A .

Note:
Such changes are observed only in the hot days when the temperature rises and causes expansion in the rail tracks. That’s why the gaps are left in between to prevent the accidents due to derailing.