Question

If the volume of a sphere is `11/21  "cm"^3`, then the radius of the sphere is ______.

Options

• 2 cm

• 4 cm

• `1/2` cm

• `1/4` cm

Answer 1

If the volume of a sphere is `11/21cm^3`, then the radius of the sphere is `bbunderline(1/2  cm)`.

Explanation:

Given,

Volume of a sphere = `11/21cm^3`  ...(i)

We know that volume of a sphere = `4/3πR^3`   ...(ii)

where, R is the radius of the sphere.

∴ `4/3πR^3 = 11/21`   [from Eqs. (i) and (ii)]

∴ `4/3 xx 22/7 xx R^3 = 11/21`

∴ `R^3 = (11 xx 21)/(21 xx 88)`

∴ `R^3 = 1/8`

∴ R= `1/2`

Hence, the radius of the sphere is `1/2`cm.