Which statement about cold rolled copper is true?

• A. Copper is not used in sheet metal.
• B. Cold rolled copper is less malleable than soft copper, but stronger.
• C. Copper weighs less than plastic.
• D. Copper cannot be formed.

Answer: (B)

Cold forming increases strength by work hardening while reducing ductility. When copper is cold rolled, the metal experiences plastic deformation at room temperature, which raises dislocation density and elongates the grains. This makes the material stronger (higher yield and tensile strength) but less ductile and malleable. Soft copper, or annealed copper, has low dislocation density and is highly ductile. So comparing cold rolled copper to soft copper, it is indeed stronger but less malleable, which is exactly what the statement says. The other ideas aren’t accurate: copper is commonly used in sheet metal, it can be formed, and it is denser than many plastics, not lighter.