Question

State three factors on which depend the linear expansion of a metal rod on heating.

Answer 1

Factors on which an increase in the length of a rod depend when heated are:

1. Length of rod L. Increase in length is directly proportional to the original length.
2. Temperature of the rod. It is directly proportional to the increase in temperature.
3. Nature of material of rod.

If L₁ is original length of rod at  t₁ °C and on heating to t₂ °C its length becomes L₂.
∴ Increase in length of rod = ( L₂ – L₁ )
and the increase in temperature ( t₂ – t₁ )
∴ [L₂ – L₁] ∝ L₁ (t₂ – t₁ )
But the increase in the length of rod does not depend on whether the rod is solid or hollow.