$\sigma_{fs} = \frac{3F_fL}{2bd^2}$ (rect. cross section), and $\sigma_{fs} = \frac{F_fL}{\pi R^3}$ (circ. cross section)
Where R is the radius of the cross section, b the width and d the height of the cross section
A three-point bending test is performed on $MgAl_2O_4$ specimen having a rectangular cross section of height d = 5 mm and width b = 6 mm. When the distance between the support points is 30 mm, the specimen fractured at 300 N. If the same test is performed on a circular cross section with radius R = 4 mm and a span (distance between the support points) of 10 mm, the fracture force will _____.
Increase
Decrease
Remain the same
