Question

Consider a beam with circular cross-section of diameter d. The ratio of the second moment of area about the neutral axis to the section modulus of the area is

• A. $\frac{d}{2}$
• B. $\frac{\pi d}{2}$
• C. d
• D. $\pi d$

Answer 1

The correct option is A $\frac{d}{2}$

$\frac{I_{NA}}{Z_{NA}}=\frac{I_{NA}}{\left(I_{NA}/Y_{max}\right)}=Y_{max}$

For a solid circular cross - section

$Y_{max}=d/2$