Surface Areas and Volumes(Class-9,Math)

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1. If the perimeter of one of the faces of a cube is 40 cm, then its volume is:

(a) 6000 cm³

(b) 1600 cm³

(d) 600 cm³

2. If the perimeter of one of the faces of a cube is 40 cm, then its volume is:

(a) 6000 cm³

(b) 1600 cm³

(d) 600 cm³

3. A cuboid having surface areas of 3 adjacent faces as a, b and c has the volume:

(a) 3abc−−−√

(b) abc−−−√

(d) (abc)²

4. The radius of a cylinder is doubled and the height remains the same. The ratio between the volumes of the new cylinder and the original cylinder is

(a) 1 : 2

(b) 3 : 1

(d) 1 : 8

5. Length of diagonals of a cube of side a cm is

(a) √2a cm

(b) √3a cm

(d) 1 cm

6. Volume of spherical shell is

(a) 23 πr³

(b) 34 πr³

(d) None of these

7. Volume of hollow cylinder

(a) π(R² – r²)h

(b) πR²h

(d) πr²(h1 – h1)

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

(a) 43 πr³

(b) 4πr³

(d) 323 πr³

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

(a) halved

(b) doubled

(d) four time

10. The total surface area of a cone whose radius is r2 and slant height 2l is

(a) 2πr(l + r)

(b) πr(l + r4)

(d) 2πrl

11. 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

(a) 1 : 4

(b) 1 : 3

(d) 2 : 1

12. The length of the longest pole that can be put in a room of dimension (10 m × 10 m × 5 m) is

(a) 15 m

(b) 16 m

(d) 12 m

13. The lateral surface area of a cube is 256 m³. The volume of the cube is

(a) 512 m³

(b) 64 m³

(d) 256 m³

14. 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

(a) 10 : 17

(b) 20 : 27

(d) 20 : 37

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

(a) 8 cm³

(b) 512 cm³

(d) 27 cm³