In a cylinder, radius is doubled
Question:

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

(a) halved

(b) doubled

(c) same

(d) four times

Solution:

(e) Let the radius be r and height be h of a cylinder.,

∴ Curved surface area of cylinder = 2πrh

We have, radius = 2r, height = h/2

New curved surface area = 2π (2r) x (h/2) = 2 πrh

Hence, the curved surface area will be same.