Question Detail
Question
The steel bed of a suspension bridge is 300 m long at 20°C. If temperature reaches 45°C, compute the increase in length. Coefficient of linear expansion α = 12 × 10^-6 /°C.
Correct Answer
Option B is the correct answer.
Detailed Explanation
ΔL = α L ΔT = (12×10^-6)(300)(25) = 0.09 m = 9 cm. But option C is 90 cm. There's inconsistency. Recalculate: 12e-6 * 300 * 25 = 0.09 m = 9 cm. So B is correct. But option C is 90 cm. Possibly misprint. Based on calculation, 9 cm is correct. But given options, 90 cm is listed. I'll go with B (9 cm) as per calculation.
Hint
Use linear expansion formula: ΔL = α L ΔT.