SURFACE AREAS AND VOLUMES

Question 1

. A cylindrical pencil sharpened at one edge is the combination of

(a) two cylinders
(b) a hemisphere and a cylinder
(c) a cone and a cylinder
(d) frustum of a cone and a cylinder

Answer 1

(c) a cone and a cylinder

Question 2

2. A shuttlecock used for playing badminton has the shape of the combination of
   (a) a cylinder and a sphere
   (b) a sphere and a cone
   (c) a cylinder and a hemisphere
   (d) frustum of a cone and a hemisphere

Answer 2

(d) frustum of a cone and a hemisphere

Question 3

3. The slant height of the frustum of a cone having radii of two ends as 5 cm and 2 cm respectively and height 4 cm is
   (a) √26 cm
   (b) 5 cm
   (c) √65 cm
   (d) 25 cm

Answer 3

(b) 5 cm

Question 4

4. The total surface area of a hemispherical solid having radius 7 cm is
   (a) 462 cm²
   (b) 294 cm²
   (c) 588 cm²
   (d) 154 cm²

Answer 4

(a) 462 cm²

Question 5

5. A solid formed on revolving a right angled triangle about its height is
   (a) cylinder
   (b) sphere
   (c) right circular cone
   (d) two cones

Answer 5

(c) right circular cone

Question 6

6. The surface area of a sphere is 616 cm2. Its radius is
   (a) 7 cm
   (b) 14 cm
   (c) 21 cm
   (d) 28 cm

Answer 6

(a) 7 cm

Question 7

7. A cylinder and a cone are of same base radius and of same height. The ratio of the volume of the cylinder to that of the cone is
   (a) 2 : 1
   (b) 3 : 1
   (c) 2 : 3
   (d) 3 : 2

Answer 7

(b) 3 : 1

Question 8

8. The volume of a sphere is 4851 cm3. Its diameter is
   (a) 3.5 cm
   (b) 7 cm
   (c) 14 cm
   (d) 21 cm

Answer 8

(d) 21 cm

Question 9

9. A piece of paper is in the shape of a semi¬circular region of radius 10 cm. It is rolled to form a right circular cone. The slant height is
   (a) 5 cm
   (b) 10 cm
   (c) 15 cm
   (d) 20 cm

Answer 9

(b) 10 cm

Question 10

10. The base radii of two circular cones of the same height are in the ratio 3 : 5. The ratio of their volumes are
    (a) 9 : 25
    (b) 5 : 3
    (c) 9 : 5
    (d) 3 : 25

Answer 10

(a) 9 : 25

Question 11

11. The curved surface area of glass having radii 3 cm and 4 cm respectively and slant height 10 cm is
    (a) 55 cm²
    (b) 110 cm²
    (c) 220 cm²
    (d) 440 cm²

Answer 11

(c) 220 cm²

Question 12

12. If two solid hemispheres of same base radius are joined together along their bases, then curved surface area of this new solid is
    (a) 3πr²
    (b) 4πr²
    (c) 5πr²
    (d) 6πr²

Answer 12

(b) 4πr²

Question 13

13. The radii of the top and bottom of a bucket of slant height 13 cm are 9 cm and 4 cm respectively. The height of the bucket is
    (a) 10 cm
    (b) 12 cm
    (c) 15 cm
    (d) 16 cm

Answer 13

(b) 12 cm