WBCS.LIVE practice question

An iron ball is heated. The percentage increase will be largest in:

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. Density
  2. Surface area
  3. Diameter
  4. Volume

Correct answer and explanation

Correct answer: Volume

Explanation: On heating, the largest percentage increase occurs in Volume of the iron ball. 📚 Other Information: ▪️ Thermal expansion affects length, area, and volume. ▪️ Linear expansion → ΔL/L. ▪️ Areal expansion → ΔA/A = 2α (double). ▪️ Volumetric expansion → ΔV/V = 3α (triple). ▪️ Hence, percentage increase is maximum in volume. ▪️ Expansion coefficient depends on the material. ▪️ Important in bridges, boilers, and engines. ▪️ Controlled by using expansion joints.