Ncert exemplar solutions mathematics class 8 Solutions for Chapter 11 mensuration

A cube of side 5 cm is painted on all its faces. If it is sliced into 1 cubic centimetre cubes, how many 1 cubic centimetre cubes will have exactly one of the

(a) 27 (b) 42 (c) 54 (d) 142

A cube of side 4 cm is cut into 1 cm cubes. What is the ratio of the surface areas of the original cubes and cut-out cubes?

(a) 1 : 2 (b) 1 : 3 (c) 1 : 4 (d) 1 : 6

A circle of maximum possible size is cut from a square sheet of board. Subsequently, a square of maximum possible size is cut from the resultant circle. What will be the area of the final square?

(a) 3/4 of the original square.

(b) 1/2 of the original square.

(c) 1/4 of the original square.

(d) 2/3 of the original square.

What is the area of the largest triangle that can be fitted into a rectangle of length l units and width w units?

(a) lw /2 (b) lw /3 (c) lw/6 (d) lw/4

If the height of a cylinder becomes 1/4 of the original height and the radius is doubled, then which of the following will be true?

(a) Volume of the cylinder will be doubled.

(b) Volume of the cylinder will remain unchanged.

(c) Volume of the cylinder will be halved.

(d) Volume of the cylinder will be1/4 of the original volume

If the height of a cylinder becomes1/4 of the original height and the radius is doubled, then which of the following will be true?

(a) Curved surface area of the cylinder will be doubled.

(b) Curved surface area of the cylinder will remain unchanged.

(c) Curved surface area of the cylinder will be halved.

(d) Curved surface area will be 1/4 of the original curved surface.

If the height of a cylinder becomes 1/4 of the original height and the radius is doubled, then which of the following will be true?

(a) Total surface area of the cylinder will be doubled.

(b) Total surface area of the cylinder will remain unchanged.

(c) Total surface of the cylinder will be halved.

(d) None of the above.

The surface area of the three coterminous faces of a cuboid are 6, 15 and 10 cm^2 respectively. The volume of the cuboid is

(a) 30 cm^3

(b) 40 cm^3

(c) 20 cm^3

(d) 35 cm^3

A regular hexagon is inscribed in a circle of radius r. The perimeter of the regular hexagon is

(a) 3r (b) 6r (c) 9r (d) 12r

The dimensions of a godown are 40 m, 25 m and 10 m. If it is filled with cuboidal boxes each of dimensions 2 m × 1.25 m × 1 m, then the number of boxes will be

(a) 1800 (b) 2000 (c) 4000 (d) 8000

The volume of a cube is 64 cm3. Its surface area is

(a) 16 cm^2 (b) 64 cm^2 (c) 96 cm^2 (d) 128 cm^2

If the radius of a cylinder is tripled but its curved surface area is unchanged, then its height will be

(a) tripled (b) constant (c) one sixth (d) one third

How many small cubes with edge of 20 cm each can be just accommodated in a cubical box of 2 m edge?

(a) 10 (b) 100 (c) 1000 (d) 10000

The area of a parallelogram is 60 cm^2 and one of its altitude is 5 cm. The length of its corresponding side is

(a) 12 cm (b) 6 cm (c) 4 cm (d) 2 cm

The perimeter of a trapezium is 52 cm and its each non-parallel side is equal to 10 cm with its height 8 cm. Its area is

(a) 124 cm^2 (b) 118 cm^2 (c) 128 cm^2 (d) 112 cm^2

Area of a quadrilateral ABCD is 20 cm2 and perpendiculars on BD from opposite vertices are 1 cm and 1.5 cm. The length of BD is

(a) 4 cm (b) 15 cm (c) 16 cm (d) 18 cm

metal sheet 27 cm long, 8 cm broad and 1 cm thick is melted into a cube. The side of the cube is

(a) 6 cm (b) 8 cm (c) 12 cm (d) 24 cm

Three cubes of metal whose edges are 6 cm, 8 cm and 10 cm respectively are melted to form a single cube. The edge of the new cube is

(a) 12 cm (b) 24 cm (c) 18 cm (d) 20 cm

A covered wooden box has the inner measures as 115 cm, 75 cm and 35 cm and thickness of wood as 2.5 cm. The volume of the wood is

(a) 85,000 cm^3 (b) 80,000 cm^3 (c) 82,125 cm^3 (d) 84,000 cm^3

The ratio of radii of two cylinders is 1: 2 and heights are in the ratio 2:3. The ratio of their volumes is

(a) 1:6 (b) 1:9 (c) 1:3 (d) 2:9

Two cubes have volumes in the ratio 1:64. The ratio of the area of a face of first cube to that of the other is

(a) 1:4 (b) 1:8 (c) 1:16 (d) 1:32

The surface areas of the six faces of a rectangular solid are 16, 16, 32, 32, 72 and 72 square centimetres. The volume of the solid, in cubic centimetres, is

(a) 192 (b) 384 (c) 480 (d) 2592

Ramesh has three containers.

(a) Cylindrical container A having radius r and height h,

(b) Cylindrical container B having radius 2r and height 1/2 h, and

(c) Cuboidal container C having dimensions r × r × h

The arrangement of the containers in the increasing order of their volumes is

(a) A, B, C

Ramesh has three containers.

(a) Cylindrical container A having radius r and height h,

(b) Cylindrical container B having radius 2r and height 1/2 h, and

(c) Cuboidal container C having dimensions r × r × h

The arrangement of the containers in the increasing order of their volumes is

(a) A, B, C

The surface area of a cuboid formed by joining two cubes of side a face to face is __________.

If the diagonals of a rhombus get doubled, then the area of the rhombus becomes __________ its original area.

If a cube fits exactly in a cylinder with height h, then the volume of the cube is __________ and surface area of the cube is __________.

The volume of a cylinder becomes __________ the original volume if its radius becomes half of the original radius.

The curved surface area of a cylinder is reduced by ____________ per cent if the height is half of the original height.

The volume of a cylinder which exactly fits in a cube of side a is __________.

The surface area of a cylinder which exactly fits in a cube of side b is __________.

If the diagonal d of a quadrilateral is doubled and the heights h1 and h2 falling on d are halved, then the area of quadrilateral is __________.

The perimeter of a rectangle becomes __________ times its original perimeter, if its length and breadth are doubled.

A trapezium with 3 equal sides and one side double the equal side can be divided into __________ equilateral triangles of _______ area.

All six faces of a cuboid are __________ in shape and of ______ area.

Opposite faces of a cuboid are _________ in area.

Curved surface area of a cylinder of radius h and height r is _______.

Total surface area of a cylinder of radius h and height r is _________

Volume of a cylinder with radius h and height r is __________.

Area of a rhombus =1/2 product of _________.

Two cylinders A and B are formed by folding a rectangular sheet of dimensions 20cm × 10 cm along its length and also along its breadth respectively. Then volume of A is ________ of volume of B.

In the above question, curved surface area of A is ________ curved surface area of B.

__ of a solid is the measurement of the space occupied by it.

__ surface area of room = area of 4 walls.