Question

In case of an area, the figure is assumed to be a lamina of negligible thickness so that its centre of gravity will be practically on the surface. As the area has no weight this point is also called the ______

(a) Moment of inertia of areas

(b) Centre of gravity

(c) Centroid

(d) Neutral axis

The question was posed to me by my school teacher while I was bunking the class.

My question is based upon Centres of Gravity and Moments of Inertia of Area in division Development of Surfaces, Isometric Projections, Perspective Projections & Transformation of Projections of Civil Engineering Drawing

Answer 1

Correct choice is (c) Centroid

To explain: In mathematics and physic, the centroid or geometric center of a plane figure is the arithmetic mean (“average”) position of all the points in the shape. The definition extends to any object in n-dimensional space: its centroid is the mean position of all the points in all of the coordinate directions. Informally, it is the point at which a cut out of the shape could be perfectly balanced on the tip of a pin.