What is the rate of linear expansion for iron?

The rate of linear expansion for iron is approximately 1.2 x 10⁻⁶ K⁻¹. This value represents how much a unit length of iron will expand for each degree increase in temperature. Understanding thermal expansion is crucial in engineering and construction, as it helps predict how materials will behave under temperature changes.

Among the options provided, 1.2 x 10⁻⁶ K⁻¹ accurately reflects the commonly accepted coefficient of linear thermal expansion for iron. This coefficient can vary slightly based on the specific composition or treatment of the iron but generally falls around this value for most standard conditions.

Insufficient values for linear expansion, such as 1.0 x 10⁻⁶ K⁻¹ and 1.5 x 10⁻⁶ K⁻¹, do not align with the established scientific data for iron. Similarly, a value like 2.0 x 10⁻⁶ K⁻¹ would indicate a greater expansion than what is typically observed in iron, which could lead to misunderstandings regarding its behavior in practical applications. Thus, the choice of 1.2 x 10⁻⁶ K⁻¹ provides a reliable estimate for the expansion