Question

Question 4
In a cylinder, the radius is doubled and height is halved, then the curved surface area will be:

A) Halved
B) Doubled
C) Same
D) Four times

Answer 1

The answer is C.
Let the radius be r and height be h of a cylinder.

$\therefore$ Curved surface area of the cylinder $=2\pi rh$

We have, radius = 2r, height $=\frac{h}{2}$

New curved surface area $=2\pi \left(2r\right)\times \frac{h}{2}=2\pi rh$

Hence, the curved surface area will be same.