The ratio of the length and diameter of a simply supported uniform circular beam which experiences maximum bending stress equal to tensile stress due to same load at its mid span, is
A. $$\frac{1}{8}$$
B. $$\frac{1}{4}$$
C. $$\frac{1}{2}$$
D. $$\frac{1}{3}$$
Answer: Option C

Bending Stress = My/I
Tensile stress = P/A
FROM QUESTION,
Bending stress = Tensile stress
i.e. My/I= P/A
Where,
M = PL/4
y=D/2
I=π D^4/64
A =π D^2/4
after putting these values
L/D = 1/2
Bending Stress = M/Z
Tensile stress = P/A
FROM QUESTION,
Bending stress = Tensile stress
i.e. M/Z = P/A
M = PL/4
Z = (Pie * D^3)/32
A = (Pie*D^2)/4
after putting these values
L/D = 1/2