Question

Let a steel bar of length '$l$', breadth 'b' and depth 'd' be loaded at the centre by a load 'W'. Then the sag of bending of beam is (Y = Young's modulus of material of steel)

• A. $\frac{W{l}^3}{2b{d}^{3}Y}$
• B. $\frac{W{l}^3}{4b{d}^{3}Y}$
• C. $\frac{W{l}^2}{2b{d}^{3}Y}$
• D. $\frac{W{l}^3}{4b{d}^{2}Y}$

Answer 1

The correct option is B $\frac{W{l}^3}{4b{d}^{3}Y}$

$\delta =\frac{W{l}^3}{4b{d}^{3}Y}$

Deflection will be maximum at center and minimum at the fixed point. The slope or deflection will be 0 mid point and maximum at fixed points