Question

A rectangle of length “a” and breadth “b” is revolved ${360}^{\circ }$ about its length. The volume of the resulting cylinder is

• A. $\pi a{b}^2$
• B. $\pi a^{2}b$
• C. $\pi ab$
• D. $2\pi ab$

Answer 1

The correct option is A

$\pi a{b}^2$

Height of the cylinder
= length of the rectangle
= a units
Radius of the cylinder
= breadth of the rectangle
= b units



Volume of the cylinder =$\pi r^{2}h$
$=\pi b^{2}a=\pi a{b}^2$