Question

47. If the radius of a cylinder is doubled, then how many times the volume is increase? a)2 b)3 c)8 AM d)None of these​

Answer 1

Answer:

Correct option is

D

8 times

let the Height of the cone=h am

Radius of the cone=r cm

Then volume of the cone=

3

1

πr

2

h

If the height and radius are double then

Height=2h

Radius=2r

Then new volume=

3

1

π(2r)

2

×2h

⇒

3

1

π×4r×2h=8×

3

1

πr

2

h

Hence it is 8 times of the old volume