Civil Engineering - Strength of Materials - Discussion

Given answer is correct.

Point of inflexion means:where BM change sign or concave to convex or point of the curve were downward to upward moment of curve and vice versa.

Point of contra flexure: where BM is zero where bending moment curve intersects zero bending moment line.

Point of virtual hinge: in continues beam, we have to provide construction etc type so it's an original joint together at the point where one can swing relative to the other.

Where BM changes its sign from +ve to -ve or -ve to +ve is called point of contraflexure and where deflection curve changes its nature from convex to concave or concave to convex is called point of inflection.
What about point of virtual hinge? Can anybody explain?

@Indu.

Point of inflexion means, that point where BM is 0 ( either BM changed sign or not )
In simply supported beam, always BM is 0 at support, this point is called a point of inflexion, & where BM changed sign only this point is called a point of contra flexture.

We say that every point of contra flexure is the point of inflexion, but all point of inflexion does not point of contra flexure.

Yes, B is correct.

Point of inflexion means where the shear force changes its sign, the point of a virtual hinge is about virtual work, the point of contra flexure means. Where the bending moment changes its sign. So, option B is correct.

Yes, B is correct.

I think it should be only B.