Physics 2004 JAMB Past Questions - Question 38: 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?

Correct Answer

C

Explanation

Safety gap = expansion of the rod

= α×L0×Δt

where α = linear expansivity of the material

L0 = Initial length of the material

Δt = Change in temperature

∴ The safety gap = 2×10^−5×20×(75−25)

= 2×10−5×10^3

= 2×10^−2m

= 0.02 m