Class 8th Mathematics MCQ

Q1. 66cm of silver is drawn into a wire 1mm in diameter. The length of the wire will be:

1. 78m

2. 84m

3. 96m

4. 108m

Ans: 2. 84m

Solution:

Volume of silver = 66cm

Diameter of wire 1mm

Radius

Then length (h)

Q2. How many bricks, each measuring 25cm × 11.25cm × 6cm, will be needed to build a wall 8m long, 6m high and

22.5cm thick?

1. 5600

2. 6000

3. 6400

4. 7200

Ans: 3. 6400

Solution:

Length of wall (l) = 8m = 800cm,

Breadth (b) = 22.5cm

Height (h) = 6m

= 600cm

Volume of wall = l × b × h = 800 × 22.5 × 600cm

= 10800000cm

Volume of bricks = 25 × 11.25 × 6cm

= 1687.5cm

Number of bricks required,

Q3. The area of the cardboard needed to make a box of size 25cm × 15cm × 8cm will be:

1. 390cm

2. 1390cm

3. 2780cm

4. 1000cm

Ans: 2. 1390cm

Solution:

Size of box = 25cm, 15cm, 8cm

Surface area = (lb + bh + hl)

= 2(25 × 15 + 15 × 8 + 8 × 25)cm

= 2(375 + 120 200)cm

= 2(695)

= 1390cm

= 1

10

∴ = 1 cm

20

= Volume

πr2

= cm 66×7×20×20

22×1×1

= 8400cm = 84cm

∴ 3

3

3

3

∴

= 10800000 = 6400

1687.5

Ans: 3. 6

Q8. The volume of a cube is 343cm . Its total surface area is:

1. 196cm

2. 49cm

3. 294cm

4. 147cm

Ans: 3. 294cm

Solution:

Volume of cube = 343cm

Side

= 7cm

Total surface area = 6(side)

= 6 × (7)

= 6 × 49cm

= 294cm

Q9. Mark against the correct answer in the following:

The circumference of the circular base of a cylinder is 44cm and its height is 15cm. The volume of the cylinder is:

1. 1155cm

2. 2310cm

3. 770cm

4. 1540cm

Q4. Which of the following statements is true?

1. The lateral faces of a square prism are triangles.

2. The lateral faces of a triangular prism can be squares or rectangles.

3. The lateral faces of a square pyramid can be squares.

4. The lateral faces of a triangular pyramid can be squares or rectangles.

Ans: 2. The lateral faces of a triangular prism can be squares or rectangles.

Q5. In the map, symbols are used to depict the different objects/ places.

1. True

2. False

Ans: 1. True

Q6. What is the name of the shape?

1. Circle

2. Square

3. Cone

4. Cylinder

Ans: 1. Circle

Q7. How many edges does a triangular pyramid have?

1. 2

2. 4

3. 6

4. 8

Ans: 2. 2310cm

Solution:

Height = 15cm

Circumference

Volume

Q10. How many faces does a cube have?

1. 6

2. 4

3. 3

4. 2

Ans: 1. 6

Q11. Mark against the correct answer in the following:

The length, breadth and height of a cuboid are in the ratio 3 : 4 : 6 and its volume is 576cm . The whole surface

area of the cuboid is:

1. 216cm

2. 324cm

3. 432cm

4. 460cm

Ans: 3. 432cm

Solution:

Volume = lbh 3x × 4x × 6x = 72x = 576cm

Total Surface area,

= 2(lb + bh + lh) = 2(3x4x + 4x6x + 3x6x) = 2(48 + 96 + 72) = 432cm

Q12. Of which shape are the faces of a cuboid?

1. Square

2. Rectangle

3. Circle

4. Triangle

Ans: 2. Rectangle

Q13. The name of the shape is:

1. Cuboid

2. Cube

3. Square

4. Cylinder

Ans: 2. Cube

Q14. If the capacity of a cylindrical tank is 1848m and the diameter of its base is 14 m, the depth of the tank is:

1. 8m

2. 12m

3. 16m

4. 18m

Ans: 2. 12m

3

= 2πr = 44cm

∴ r = = 7cm 44×7

2×22

∴ = πr2h = 22 × 7 × 7 × 15 = 2310cm3

⇒ x = √3 = 2 576

72

∴

2

3

Solution:

Capacity of cylindrical tank = 1848m

Diameter = 14m

Q15. A cylinder has ____.

1. Two bases which are congruent triangles.

2. Two bases which may or may not be congruent.

3. One base which is a circle.

4. Two bases which are congruent circles.

Ans: 4. Two bases which are congruent circles.

Q16. A polyhedron is said to be regular if its faces are made up of regular polygons and the same number of faces

meet at each vertex.

1. True

2. False

Ans: 1. True

Q17. The lateral faces of a pyramid are____.

1. Triangles

2. Pentagons

3. Rectangles

4. None of these

Ans: 1. Triangles

Q18. The top-view of a cube looks like a:

1. Circle

2. Square

3. Rectangle

4. Triangle

Ans: 2. Square

Solution:

Since all the faces of a cube are of equal length.

Q19. What is the flat surface of a solid figure called?

1. Vertex

2. Face

3. Edge

4. Solid

Ans: 2. Face

Q20. The following is the map of a town. Based on it answer question 19 – 21.

The number of hospitals in the town is

1. 1

2. 2

3. 3

3

∴ Radius(r) = = 7m 14

2

∴ Depth = Volume =

πr2

1848×7

22×7×7

= = 12m 264

22

4. 4

Ans: 2. 2

Solution:

Q21. If each side of a cube is doubled, its surface area:

1. Is doubled.

2. Becomes 4 times.

3. Becomes 6 times.

4. Becomes 8 times.

Ans: 2. Becomes 4 times.

Solution:

Let side of cube in frist case = a

Then surface area = 6a

And side of second cube = 2a

Surface area = 6(2a) = 6 × 4a = 24a

Ratio

Becomes 4 times.

Q22. Which of the following is the top view of the given shape?

Ans: 1.

Solution:

Since, top view is the picture of the solid which is seen from the top of the given figure. Therefore, the option (a) figure will be the top

view, i.e.,

Q23. Mark against the correct answer in the following:

The surface area of a cube is 384cm . Its volume is:

1. 512cm

2. 256cm

3. 384cm

4. 320cm

Ans: 1. 512cm

Solution:

Surface area = 6a

Volume

Q24. Which is the three-dimensional figure formed by rotating a triangle?

1. Cone

2. Quadrilateral

3. Prism

4. Square

Ans: 1. Cone

Q25. What is the number of corners in a cylinder?

1. 1

2. 2

3. 3

4. 0

⇒ 6a2 = 384

⇒ a = √ = √64 = 8cm 384

6

∴ = a2 = 83 = 512cm3

Ans: 4. 0

Q26. Solid having only line segments as its edges is a:

1. Polyhedron.

2. Cone.

3. Cylinder.

4. Polygon.

Ans: 1. Polyhedron.

Solution:

in polyhedrin, the faces meet at edges which are line segments and edges meet at vertes.

Q27. A rectangular water tank is 3m long, 2m wide and 5m high. How many litres of water can it hold?

1. 30000

2. 15000

3. 25000

4. 35000

Ans: 1. 30000

Solution:

Length of water tank (l) = 3m

Width (b) = 2m

And height (h) = 5m

Volume = lbh = 3 × 2 × 5 = 30m

Water in it = 30 × 1000

= 30000

Q28. According to the map, the number of schools in the town is:

1. 4

2. 3

3. 5

4. 2

Ans: 3. 5

Solution:

Clearly,

Q29. See the following solid and answer the following questions:

The number of edges is:

1. 5

2. 10

3. 20

4. 15

Ans: 4. 15

Q30. A cube is a 3D shape.

1. True

2. False

Ans: 1. True

Q31. How many edges does a cuboid have?

1. 12

2. 8

3. 6

4. 4

Ans: 1. 12

Q32. In a solid if F = V = 5, then the number of edges in this shape is

1. 6

2. 4

3. 8

4. 2

Ans: 3. 8

Solution:

Euler formula for any polyhedron is

F + V – E = 2

Given, F = V = 5

On puttting the values of F and V in the Euler’s formula, we get

5 + 5 – E = 2

⇒ 10 – E = 2 ⇒ E – 8

Note: F = fraces, V = vertices and E = edges.

Q33. The ratio of the number of general stores and that of the ground is:

1. 1 : 2

2. 2 : 1

3. 2 : 3

4. 3 : 2

Ans: 4. 3 : 2

Solution:

Clearly,

Hence, ratio of the number of general stres and that of the ground is

Q34. Mark against the correct answer in the following:

A cuboid having dimensions 16m × 11m × 8m is melted to form a cylinder of radius 4m. What is the height of the

cylinder?

1. 28m

2. 14m

3. 21m

4. 32m

Ans: 1. 28m

Solution:

Volume of the cuboid = 16 × 11 × 8 = 1408m

Volume of the cylinder

Q35. Which of the following is the base of a tetrahedron?

1. A square.

2. A rectangle.

3. A circle.

4. A triangle.

Ans: 4. A triangle.

Solution:

The tetrahedron is one kind of pyramid, which is a polyhedron with a flat polygon base and triangular faces connecting the base to a

common point. In the case of a tetrahedron the base is a triangle (any of the four faces can be considered the base), so a tetrahedron

is also known as a “triangular pyramid”.

Q36. The side-view of a cone appears as:

1. Circle

2. Square

3. Rectangle

4. Triangle

Ans: 4. Triangle

Q37. Which of the statements is true?

1. The square pyramid has 4 triangular faces and 1 square base.

2. The triangular prism has 4 triangular faces and 1 square base.

3. The triangular prism has 3 triangular faces and 2 square bases.

4. The square pyramid has 4 triangular faces and 2 square bases.

Ans: 1. The square pyramid has 4 triangular faces and 1 square base.

Q38. The name of the shape is:

1. Cylinder

2. Square

3. Circle

4. Triangle

Ans: 2. Square

Q39. How many vertices does a cuboid have?

1. 4

2. 6

3. 8

4. 3

Ans: 3. 8

Q40. Which of the statements is true?

1. A cylinder has two rectangular bases.

2. A cone has one circular base.

3. A cone has one rectangular base.

4. A cylinder has three circular bases.

Ans: 2. A cone has one circular base.

Q41. If the base of a prism is a polygon of ‘n’ sides, then which of the following is the number of faces of the prism?

1. n + 2

2. n + 1

3. n

4. n – 1

Ans: 1. n + 2

Solution:

If the base of a prism is polygon with n sides the total faces are n + 2.

E.g. in a triangular prism base is triangle (3 sides) and total faces are 5 = 3 + 2.

Q42. If each side of a cube is doubled then its volume:

1. Is doubled.

2. Becomes 4 times.

3. Becomes 6 times.

4. Becomes 8 times.

Ans: 4. Becomes 8 times.

Solution:

Let side of cube in frist case = a

Then volume = a

If side of cube is doubled, then side = 2a

Volume (2a) = 8a

Becomes 8 times.

Q43. A cuboid has how many faces?

1. 2

2. 4

3. 6

4. 3

Ans: 3. 6

Q44. 3D objects have the same views from different positions.

1. True

2. False

Ans: 2. False

Solution:

3D objects have different views from different positions.

Q45. Which amongst the following is not a polyhedron?

Ans: 3.

3

3 3

Solution:

According to the definition of a polyhedron, option (c) figure does not satisfies the condition of a polyhedron.

Since, a solid is a polyhedron if it is made up of only polygonal-faces, the faces meet at edges with one line segment and the edges

meeting at a point. The point is generally called as vertex. But all the faces of option (c) are not polygons, there is a circular base, so

the figure is not a polyhedron

Q46. How many vertices does a cube have?

1. 8

2. 6

3. 4

4. 2

Ans: 1. 8

Q47. The faces of a cube consist of.

1. 8 squares.

2. 4 squares and 2 rectangles.

3. 2 squares and 4 rectangles.

4. 6 squares.

Ans: 4. 6 squares.

Q48. Which of the following can be the base of a pyramid?

1. Line segment.

2. Circle.

3. Octagon.

4. Oval.

Ans: 3. Octagon.

Solution:

Since, a pyramid is a polyhedron base a polygon and lateral faces are triangles.

Hence, octagon can be the base of a pyarmid.

Q49. Which of the following is the number of vertices of sphere?

1. 0

2. 1

3. 2

4. 4

Ans: 1. 0

Solution:

A sphere does not have any vertices because it doesn’t have faces or edges.

Q50. How many cubes of 10cm edge can be put in a cubical box of 1m edge?

1. 10

2. 100

3. 1000

4. 10000

Ans: 3. 1000

Solution:

Edge of cube = 10cm

Volume = a3 = (10)3 = 1000cm3

Edge of box = 1m = 100cm

Volume = (100) = 1000000cm

No. of cubes

Q51. Which of the following is the other name of a cube?

1. A tetrahedron.

2. A regular hexahedron.

3. A square antiprism.

4. A cuboctahedron.

Ans: 2. A regular hexahedron.

Solution:

The cube can also be called a regular hexahedron. It is one of the five regular polyhedrons, which are also sometimes referred to as

the Platonic solids.

Q52. What is the name of the given shape?

1. Square

2. Rectangle

3. Cuboid

4. Cube

Ans: 4. Cube

Q53. Which of the following is a triangular pyramid having all the faces as equilateral triangle?

1. Rectangular pyramid.

2. Square pyramid.

3. Tetrahedron.

4. None of these.

Ans: 3. Tetrahedron.

Solution:

The triangular pyramid with all the faces of the equilateral triangle is called tetrahedron.

Q54. Which of the following statements is false?

1. A sphere has one flat surface.

2. A cone has one flat face.

3. A cylinder has two circular faces.

4. A sphere has one curved face.

Ans: 1. A sphere has one flat surface.

Q55. Find the side of a cube whose surface area is 2400cm . 

∴ 3 3

= = 1000 1000000

1000

2

1. 20cm

2. 15cm

3. 10cm

4. 25cm

Ans: 1. 20cm

Q56. See the following solid and answer the following questions:

The number of faces is:

1. 6

2. 7

3. 8

4. 9

Ans: 2. 7

Q57. For a polyhedron, if ‘F’ stands for number of faces, V stands for number of vertices and E stands for number of

edges, then which of the following relationships is named as Euler’s formula?

1. F + V = E + 2

2. F + E = V + 2

3. V + E = F + 2

4. F + V = E – 2

Ans: 1. F + V = E + 2

Q58. What do you call solid figures with line segments as their edges?

1. Polygons

2. Squares

3. Cylinders

4. Polyhedrons

Ans: 4. Polyhedrons

Q59. The ratio of the total surface area to the lateral surface area of a cylinder whose radius is 20cm and height 60cm,

is:

1. 2 : 1

2. 3 : 2

3. 4 : 3

4. 5 : 3

Ans: 3. 4 : 3

Solution:

Radius of a cylinder (r) = 20cm

And height (h) = 60cm

Leteral surface area

And total surface area

Ratio

∴ = 2πrh

= 2 × π × 20 × 60 = 24000π

= 2πrh + 2πh2

= 24000π + 2π × 20 × 20

= 24000π + 800π = 3200π

∴ 3200π : 2400π

⇒ 4 : 3

Q60. The height of a cylinder is 14cm and its diameter is 10cm. The volume of the cylinder is:

1. 1100cm

2. 3300cm

3. 3500cm

4. 7700cm

Ans: 1. 1100cm

Solution:

Diameter of cylinder = 10cm

Radius (r)

Height (h) = 14cm

Volume

Q61. How many numbers of faces does a hemisphere has?

1. 1

2. 2

3. Many

4. None of these.

Ans: 2. 2

Solution:

This is because of the earth’s axis which divides the earth into 2 equal parts called hemispheres.

Q62. If a polyhedron has 6 vertices and 12 edges. What is the number of faces it has?

1. 6

2. 8

3. 12

4. 18

Ans: 2. 8

Solution:

By Euler’s formula we know that:

For any polyhedron,

F + V – E = 2

F = 2 – V + E

F = 2 – 6 + 12

= 8

Q63. What is the number of flat surfaces of a cone?

1. 1

2. 2

3. 3

4. 0

Ans: 1. 1

Q64. How many numbers of vertices does a cone has?

1. 1

2. 2

3. 3

4. None of these.

Ans: 1. 1

Solution:

A cone has 1 flat surface (the circle at the top) and technically 1 vertex.

(IMAGE)

= = 5cm 10

2

∴ = πr2h

= 22 × 5 × 5 × 14cm3

7

= 1100cm3

Q65. Prisms and Pyramids are:

1. Polygons

2. Cubes

3. Polyhedrons

4. Spherical shapes

Ans: 3. Polyhedrons

Q66. A circular well with a diameter of 2 metres, is dug to a depth of 14 metres. What is the volume of the earth dug

out?

1. 32m

2. 36m

3. 40m

4. 44m

Ans: 4. 44m

Solution:

Diameter of circular well = 2n

Radius

Depth (h) = 14m

Volume of earth dug out

Q67. How many edges does a pyramid with square base have?

1. 8

2. 6

3. 4

4. 5

Ans: 1. 8

Q68. In a blueprint of a room, an architect has shown the height of the room as 33cm. If the actual height of the room

is 330cm, then the scale used by her is:

1. 1:11

2. 1:10

3. 1:100

4. 1:3

Ans: 2. 1:10

Solution:

Given, in a blueprint height of the room = 33cm, and actual height of the room = 330cm

We know that,

Q69. Which of the statements is true?

1. The triangular prism has 3 triangular faces and 2 square bases.

2. The square pyramid has 4 triangular faces and 1 square base.

3. The square pyramid has 4 triangular faces and 2 square bases.

4. The triangular prism has 4 triangular faces and 1 square base.

Ans: 2. The square pyramid has 4 triangular faces and 1 square base.