Two beams of equal cross sectional areas are subjected to equal bending moment. If one beam has square section and the other has circular section then
- A. Both the beams will be equally strong
- B. Square section beam will be stronger
- C. Circular section beam will be stronger
- D. Depends on loading condition
Answer: B. Square section beam will be stronger
Explanation: For equal area, the section modulus Z of a square is higher than that of a circle ($a³/6 > \pi r³/4$). Higher Z means lower stress, hence stronger.