Question

If a bimetallic strip is heated it will:

• A. Bend towards the metal with lower thermal expansion coefficient.
• B. Bend towards the metal with higher thermal expansion coefficient.
• C. Twist itself into a helix.
• D. Have no bending.

Answer 1

The correct option is A Bend towards the metal with lower thermal expansion coefficient.

When a material is heated, it expands in length by an amount equal to αΔT, where α is the coefficient of linear thermal expansion and ΔT is the change in temperature.

The metal which expands the most will therefore be the one which has the largest coefficient of linear thermal expansion.

a bimetallic strip is heated it will bend towards the metal with lower thermal expansion coefficient.