Change in the length of a material due to a change in temperature, ΔT is given as,
Where L is the initial length of the material and α is the coefficient of linear expansion.
It is clear from the above equation that the expansion of a material is proportional to its coefficient of linear expansion.
From the table, Coefficient of expansion of steel,α₁=12.00
and, Coefficient of expansion of brass is, α₂=19.00
As the coefficient of expansion of brass is more than that of steel, brass will expand more than steel.