Volume and Surface Area Class 9

The Curved surface area of a right circular cylinder is 4.4 sq.cm. The radius of the base is 0.7 cm. The height of the cylinder will be:

• 2 Cm

• 3 Cm

• 1 Cm

• 1.5 Cm

The radius of a hemispherical balloon increases from 6 cm to 12 cm as air is being pumped into it. The ratio of the surface areas of the balloon in the two cases is

• 1:4

• 1:3

• 2:3

• 2:1

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

• 8 cm³ 

• 512 cm³

• 64 cm³

• 27 cm³

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

• 2.4 cm

• 2.1 cm

• 1.6 cm

The number of planks of dimensions (4 m × 50 cm × 20 cm) that can be stored in a pit that is 16 m long, 12m wide and 4 m deep is

• 1900

• 1920

• 1800

• 1840

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

A well with 10 m inside diameter is dug 14m deep. Earth taken out of it is spread all around it to make an embankment of height 4 2/3 m. Find the width of the embankment.

• 5m

• 4m

• 4.3m

• 6m

If the radius of a sphere is doubled, then what is the ratio of their surface area?

• 1 : 2

• 2 : 1

• 1 : 4

• 4 : 1

 If the radius of cylinder is halved and height is doubled, then what will be the curved surface area?

• increase by 1

• the same

• double

• triple

A conical tent is 15m high and the radius of its base is 20m. The cost of canvas required to make the tent at the price of Rs. 7 per m sqaure

• Rs.10000

• Rs.12000

• Rs.11000

• Rs.9000