Which statement about coefficient of thermal expansion is supported by the material?

• A. It describes how the size of a material changes with temperature.
• B. It describes electrical resistance changes with temperature.
• C. It describes magnetic properties changes with temperature.
• D. It describes chemical composition changes with temperature.

Answer: (A)

The main concept here is how a material’s size changes with temperature. The coefficient of thermal expansion quantifies the fractional change in length (or other dimension) per degree of temperature change, typically written as ΔL/L0 ≈ α ΔT. In other words, it describes how much a material expands or contracts as the temperature rises or falls, which is a purely dimensional effect.

That’s why the statement describing size changes with temperature is the correct interpretation. The other options pertain to different temperature-dependent properties—electrical resistance, magnetic properties, or chemical composition—not to how dimensions respond to temperature.