Question

A metal bar expands by 1.0 mm when its temperature is increased by 1.0 C. Which of the following statements about this bar must be true? (There may be more than one correct choice.)

A. It will expand by more than 1.0 if its temperature is increased by 1.0 .
B. It will expand by less than 1.0 if its temperature is increased by 1.0 .
C. It will expand by 2.0 if its temperature is increased by 2.0 .
D. It will expand by more than 2.0 mm if its temperature is increased by 2.0 .

Answer 1

(C) must be true because the coefficient is a constant and its expansion must be "proportional" to the temperature change

ΔL = L0 ρ ΔT where ρ is the coefficient of linear expansion