Choose one of the assumptions for Macaulay's method of slope and deflection?

The deflections are large.

The material is isotropic.

(\frac {dy} {dx})² is negligible compared to unity, where \frac {dy} {dx} is the deflection.

This theory holds good if the deflections are of the order of less than 1/6 th the depth of beam.

Solution

Correct option is B

Assumptions of Macaulay’s Method
In addition to the usual beam theory assumptions (such as homogeneous and isotropic material, ideal supports, etc.), the following assumptions are made.
The deflections are small, and therefore the square of the slope is negligible:
$\left(\frac{dy}{dx}\right)^2 \ll 1$
$\text{where } \frac{dy}{dx} \text{ is the slope of the deflection curve.}$
The method is valid when the maximum deflection is small, typically less than one-tenth of the depth of the beam.