Question

The dimensions of a symmetrical welded I - Section are shown in the figure. The plastic section modulus about the weaker axis (in ${\text{cm}}^3$, upto one decimal place) is

• A. 114.1

Answer 1

The correct option is A 114.1

Weaker axis implies y - y axis.
$\therefore Z_{Py}=\frac{A}{2}(\overline{x_1}+\overline{x_2})$
$=\left[\frac{150\times 10}{2}\right(37.5+37.5\left)\right]\times 2+[\frac{(200-20)\times 6}{2}\times (\frac{3}{2}+\frac{3}{2})]$
$=112500+1620$
$=114120{\text{mm}}^3$
$=114.1{\text{cm}}^3$