Q83 of 189 Page 512

A right circular cylinder just encloses a sphere of radius (as shown in the figure). Then, the surface area of the sphere is equal to the curved surface area of the cylinder.

True

Curved surface area of a sphere

Radius of cylinder = r + r = 2r

Curved surface area of a cylinder = =

The question consists of two statements, namely, Assertion (A) and Reason (R). Please select the correct answer.

Assertion (A)	Reason (R)
If the radius of a sphere is doubled then the ratio of the volume of the first sphere to that of the second is 1 : 8.	A cone and a hemisphere have equal bases and equal volumes. The ratio of their heights is 1 : 2.

The question consists of two statements, namely, Assertion (A) and Reason (R). Please select the correct answer.

Assertion (A)	Reason (R)
The curved surface area of a cone is and its diameter is 14 cm. Then, its slant height is 25 cm.	The curved surface area of a cone having base radius and slant height is

The largest possible right circular cone is cut out of a cube of edge cm. The volume of the cone is

If a sphere is inscribed in a cube, then the ratio of the volume of the cube to the volume of the sphere will be