Question Detail
Question
The coefficient of thermal expansion, α, of a metal bar of length l whose length expands by Δl when its temperature increases by ΔT is given by Δl = α l ΔT. What is the dimension of α?
Correct Answer
Option A is the correct answer.
Detailed Explanation
From Δl = α l ΔT, α = Δl / (l ΔT). Δl and l have the same dimension (L), so α has dimension 1/ΔT, which is K⁻¹ (or more generally, temperature inverse).
Hint
Rearrange the formula to solve for α and perform dimensional analysis.