Question

If the height and the radius of a cone are doubled, the volume of the cone becomes
A. 3 times
B. 4 times
C. 6 times
D. 8 times

Answer 1

Correct Answer - D
Volume of a cone of height h and radius `r = (1)/(3) pi r^(2) h = V`
New height = 2h and new radius = 2r
`:.` new volume `= (1)/(3) pi (2r)^(2) xx 2h = 8 xx ((1)/(3) pi r^(2) h) = 8V`