Correct option is A
Assumptions in the theory of bending:
Plane section remain plane before bending even after bending.
The material of the beam is isotropic and homogeneous.
follows Hook’s law.
The stress-induced is proportional to the strain and the stress at any point does not exceed the elastic limit.
The beam is initially straight and has a uniform cross-section.
The modulus of elasticity is the same for the beam under tension or compression.
The beam is subjected to pure bending and therefore bends in an arc of a circle.
The radius of curvature is large compared to the dimensions of the section.
The loads are applied in the plane of bending.
The transverse section of the beam is symmetrical about a line passing through the center of gravity in the plane of bending.
