Surface Area & Volume_1

The radius of a sphere is 2r, then its volume will be

The total surface area of a cube is 96 cm2. The volume of the cube is:

A cone is 8.4 cm high and the radius of its base is 2.1 cm. It is melted and recast

into a sphere. The radius of the sphere is

• 4.2 cm

• 2.1 cm

• 2.4 cm

• 1.6 cm

In a cylinder, radius is doubled and height is halved, curved surface area will be

• halved

• doubled

• same

• four times

The radii of two cylinders are in the ratio of 2:3 and their heights are in the ratio of

5:3. The ratio of their volumes is:

• 10 : 17

• 20 : 27

• 17 : 27

• 20 : 37

The number of planks of dimensions (4 m × 50 cm × 20 cm) that can be stored in

a pit which is 16 m long, 12m wide and 4 m deep is

• 1900

• 1920

• 1800

• 1840

The length of the longest pole that can be put in a room of dimensions

(10 m × 10 m × 5m) is

• 15 m

• 16 m

• 10 m

• 12 m

The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being

pumped into it. The ratios of the surface areas of the balloon in the two cases is

• 1 : 4

• 1 : 3

• 2 : 3

• 2 : 1