Q7 of 70 Page 21

If the ratio of volumes of two spheres is 1: 8, then the ratio of their surface areas is

Ratio of volume of spheres = (ratio of radius)3


Given, ratio of volumes of two spheres is 1: 8


⇒ (ratio of radius)3 = 1 : 8


⇒ ratio of radius = 1 : 2


Ratio of surface area = (ratio of radius)2


⇒ Ratio of surface area = 1 : 4

More from this chapter

All 70 →
5

The largest sphere is cut off from a cube of side 6 cm. The volume of the sphere will be

 6

A cylindrical rod whose height is 8 times of its radius is melted and recast into spherical balls of same radius. The number of balls will be

 8

If the surface area of a sphere is 144πm2, then its volume (in m3) is

 9

If a solid sphere of radius 10 cm is moulded into 8 spherical solid balls of equal radius, then the surface area of each ball (in sq. cm) is