The volume of a sphere is equal to two -thrid of the volume of a cylinder whose height and diameter are equal to the diameter of the sphere.

Explanation

True
Let the radius of the sphere and cylinder be r.
Given, height of the cylinder = diamter of the bases
`rArr" "h = 2r`
According to the given condition,
Volume of sphere `= (2)/(3) xx` volume of cylinder
`rArr" " (4)/(3) pir^(3) = (2)/(3) xx pir^(2) xx 2r`
`rArr" " (4)/(3) pir^(3) = (4)/(3) pi r^(3)`
Hence, the volume of a sphere is equal to two-third of the volume of a cylinder.