Mathematics

Problem

If the surface area of a sphere of radius

r

is increasing uniformly at the rate

8\text{cm}^2/\text{s}

, then the rate of change of its volume is : [JEE-Main (On line)-2013] (1) proportional to

r^2

(2) constant (3) proportional to

r

(4) proportional to

\sqrt{r}