Question

If the radies of a cylinder is doubled and
height is halved, then curved surface areas will be
a) halved (b)doubled (c) same) (d) four times
​

Answer 1

ⓢⓞⓛⓤⓣⓘⓞⓝ

let radius of the cylinder=7 unit

height of the cylinder=10 unit

to solve the sum we use the formula of curved surface area of the cylinder

the formula is 2πrh(here r is radius and h is height)

therefore curved surface area of the cylinder=2×22/7×7×10 unit²

=440 unit ²

After doubling the radius the radius=7×2=14 unit

after halfing the height height =10/2=5 unit

therefore curved surface area of the cylinder=2πrh

=2×22/7×14×5unit²

=440 unit²

so the answer is same i.e answer is remain unchanged

Answer 2

Answer:

opposition (c) is correct ,curved surface area remains same.

Step-by-step explanation:

Curved surface area of Cylinder=2πrh

Given=r=2r , h=h/2

Therefore , Curved surface area of the cylinder =2πrh

=2π(2r)(h/2)

=2πrh.