Question

A solid cylinder of radius r and height h is placed over other cylinder of same height and radius. The total surface area of the shape so formed is:

• A. $4\pi rh+4\pi r^2$
• B. $4\pi rh$
• C. $\pi rh+\pi r^2$
• D. $4\pi rh-\pi r^2$

Answer 1

The correct option is A $4\pi rh+4\pi r^2$

Radius and height of both cylinders are same .

Now , total surface area of this shape

$=(2\pi rh+\pi r^2+\pi r^2)+(2\pi rh+\pi r^2+\pi r^2)=(4\pi rh+4\pi r^2)$