The radius of a circle is increasing uniformly at the rate of 4 cm/sec. Find the rate at which the area of the circle is increasing when the radius is 8 cm.

The radius of a circle is increasing uniformly at the rate of 3 cm/s. Find the rate at which the area of the circle is increasing when the radius is 10 cm.

Radius of a circle is increasing at rate of 3 cm//sec Find the rate at which the area of circle is increasing at the instant when radius is 10 cm.

The radius of a circle is increasing at the rate of 0.5cm/sec. Find the rate of increase of its circumference.

The radius of a circle is increasing at the rate of 0.7 cm/sec. What is the rate of increase of its circumference?

If the radius of a circle is increasing at the rate of 2 cm/ sec, then the area of the circle when its radius is 20 cm is increasing at the rate of

If the radius of a circle is increasing at a uniform rate of 2 cm/s, then find the rate of increase of area of circt the instant when the radius is 20 cm.

A circular disc of radius 3 cm is being heated. Due to expansion, its radius increases at the rate of 0.05 cm/sec. Find the rate at which its area is increasing when radius is 3.2 cm.

The radius of a sphere is increasing at the rate of 0.2 cm/sec. The rate at which the volume of the sphere increases when radius is 15 cm, is

The radius of a circle is increasing at the rate of 0.7 cm/s. What is the rate of increase of its circumference?

(i) The radius of a circle is increasing at the rate of 5 cm/sec. Find the rate of increasing of its perimeter. (ii) If the area of a circle increases at a constant rate, then show that the rate of increase of its circumference is inversely proportional to its radius.