Multiple choice

While laying railway tracks, gaps have to be left between successive lengths of rails to allow for _____.

  1. contraction during the summer

  2. expansion during the summer

  3. increase in friction

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Metal rails expand when heated during summer due to thermal expansion. If no gaps are left, the expanding rails would buckle and bend, causing derailment risks. The gaps (expansion joints) provide space for this expansion.

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