Question

If the radius of cylinder is halved and height is doubled then what will be the curved surface area?
(a) Increase by 1 (b) the same (c) double
(b) the same
(c) double
(d) triple​

Answer 1

answer

let initial radius be x

final be x/2

let initial height be h

final be 2×h

initial curved surface area of cylinder. = 2πrh.......(1)

final curved surface area =

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: 2\pi \frac{r}{2} \times 2h$

=2πrh.........(2)

from 1 and 2 since both r same

so option b is correct

hope this will help you