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JAMB Physics 1990 Question 16

Question 16

Thermal Expansion

A bar of initial length l0 is heated through a temperature change Δt to a new length l. The linear expansivity, α, of the bar is

  1. A.(l − l0)/(lΔt)
  2. B.(l − l0)/(l0Δt)
  3. C.l0(1 + Δt)
  4. D.(l − l0)/(l(1 + Δt))
Show the answer and explanation

Answer: B ((l − l0)/(l0Δt))

Explanation

Linear expansivity = increase in length ÷ (original length × temperature change) = (l − l0)/(l0Δt).