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JAMB Physics 2004 Question 38

Question 38

Thermal Expansion

Metal rods of length 20m each are laid end to end to form a bridge at 25°C. What gap will be provided between consecutive rails for the bridge to withstand 75°C? [Linear expansivity of the material = 2.0 × 10−5 K−1]

  1. A.0.22m
  2. B.0.25m
  3. C.0.02m
  4. D.0.20m
Show the answer and explanation

Answer: C (0.02m)

Explanation

Expansion = αLΔθ = 2.0 × 10−5 × 20 × 50 = 0.02 m, so the gap must be 0.02 m.