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Ch-11: Introduction to Three Dimensional Geometry 30 Questions

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Try each question on your own first. Use the Show Answer button only after you have selected your option, then read the explanation and revise the related concept from your chapter notes.

1. Into how many octants do the coordinate planes divide three-dimensional space?

  • A. 8
  • B. 4
  • C. 6
  • D. 12

2. The coordinates of origin in 3D space are:

  • A. (0, 0, 0)
  • B. (0, 0)
  • C. (1, 1, 1)
  • D. (0, 1, 0)

3. A point lies on the x-axis. What are its y and z coordinates?

  • A. y = 0, z = 0
  • B. x = 0, y = 0
  • C. x = 0, z = 0
  • D. x = 1, y = 1

4. The point (2, -3, 4) lies in which octant?

  • A. IV octant
  • B. I octant
  • C. II octant
  • D. V octant

5. Distance of point P(x, y, z) from the origin is given by:

  • A. √(x² + y² + z²)
  • B. x + y + z
  • C. √(x² + y²)
  • D. x² + y² + z²

6. Distance between points P(x₁, y₁, z₁) and Q(x₂, y₂, z₂) is:

  • A. √((x₂ - x₁)² + (y₂ - y₁)² + (z₂ - z₁)²)
  • B. (x₂ - x₁) + (y₂ - y₁) + (z₂ - z₁)
  • C. √((x₂ + x₁)² + (y₂ + y₁)² + (z₂ + z₁)²)
  • D. √((x₂ - x₁)² + (y₂ - y₁)²)

7. Find distance between points (1, 2, 3) and (4, 6, 3):

  • A. 5
  • B. 25
  • C. √10
  • D. 7

8. Midpoint of line joining (x₁, y₁, z₁) and (x₂, y₂, z₂) is:

  • A. ((x₁+x₂)/2, (y₁+y₂)/2, (z₁+z₂)/2)
  • B. ((x₁-x₂)/2, (y₁-y₂)/2, (z₁-z₂)/2)
  • C. (x₁+x₂, y₁+y₂, z₁+z₂)
  • D. ((x₁+x₂)/3, (y₁+y₂)/3, (z₁+z₂)/3)

9. Coordinates of point dividing segment in ratio m : n internally are:

  • A. ((mx₂ + nx₁)/(m+n), (my₂ + ny₁)/(m+n), (mz₂ + nz₁)/(m+n))
  • B. ((mx₂ - nx₁)/(m-n), (my₂ - ny₁)/(m-n), (mz₂ - nz₁)/(m-n))
  • C. ((mx₁ + nx₂)/(m+n), (my₁ + ny₂)/(m+n), (mz₁ + nz₂)/(m+n))
  • D. ((x₁ + x₂)/m, (y₁ + y₂)/m, (z₁ + z₂)/m)

10. Coordinates of point dividing segment in ratio m : n externally are:

  • A. ((mx₂ - nx₁)/(m-n), (my₂ - ny₁)/(m-n), (mz₂ - nz₁)/(m-n))
  • B. ((mx₂ + nx₁)/(m+n), (my₂ + ny₁)/(m+n), (mz₂ + nz₁)/(m+n))
  • C. ((nx₁ - mx₂)/(m-n), (ny₁ - my₂)/(m-n), (nz₁ - mz₂)/(m-n))
  • D. ((mx₁ - nx₂)/(m-n), (my₁ - ny₂)/(m-n), (mz₁ - nz₂)/(m-n))

11. Centroid of a triangle with vertices (x₁, y₁, z₁), (x₂, y₂, z₂), and (x₃, y₃, z₃) is:

  • A. ((x₁+x₂+x₃)/3, (y₁+y₂+y₃)/3, (z₁+z₂+z₃)/3)
  • B. ((x₁+x₂+x₃)/2, (y₁+y₂+y₃)/2, (z₁+z₂+z₃)/2)
  • C. (x₁+x₂+x₃, y₁+y₂+y₃, z₁+z₂+z₃)
  • D. ((x₁+x₂)/3, (y₁+y₂)/3, (z₁+z₂)/3)

12. The point (-3, 1, -2) lies in which octant?

  • A. VI octant
  • B. III octant
  • C. VII octant
  • D. II octant

13. In xy-plane, the z-coordinate of any point is always:

  • A. 0
  • B. 1
  • C. Any constant
  • D. Undefined

14. In yz-plane, which coordinate is always zero?

  • A. x
  • B. y
  • C. z
  • D. None

15. Distance of point P(3, 4, 5) from xy-plane is:

  • A. 5 units
  • B. 3 units
  • C. 4 units
  • D. √(3² + 4²) = 5

16. Distance of point P(3, 4, 5) from x-axis is:

  • A. √(y² + z²) = √41
  • B. 3
  • C. 4
  • D. 5

17. Find midpoint of line joining (2, 3, 4) and (4, 7, 8):

  • A. (3, 5, 6)
  • B. (6, 10, 12)
  • C. (1, 2, 2)
  • D. (2, 4, 4)

18. The octant in which all three coordinates are negative (-, -, -) is:

  • A. VII octant
  • B. VIII octant
  • C. III octant
  • D. V octant

19. Reflection of point (2, 3, 5) in xy-plane is:

  • A. (2, 3, -5)
  • B. (-2, 3, 5)
  • C. (2, -3, 5)
  • D. (-2, -3, -5)

20. Reflection of point (2, 3, 5) in yz-plane is:

  • A. (-2, 3, 5)
  • B. (2, -3, 5)
  • C. (2, 3, -5)
  • D. (-2, -3, 5)

21. Foot of perpendicular from point (2, 3, 4) on x-axis is:

  • A. (2, 0, 0)
  • B. (0, 3, 0)
  • C. (0, 0, 4)
  • D. (2, 3, 0)

22. Foot of perpendicular from point (2, 3, 4) on xy-plane is:

  • A. (2, 3, 0)
  • B. (2, 0, 4)
  • C. (0, 3, 4)
  • D. (2, 0, 0)

23. If points (1, 1, 1), (0, 0, 0) and (x, y, z) are collinear, then:

  • A. x = y = z
  • B. x + y + z = 0
  • C. x + y = z
  • D. x = y = -z

24. Distance between points (0, 0, 0) and (-3, 4, 12) is:

  • A. 13
  • B. 12
  • C. 5
  • D. √169 = 13

25. Centroid of triangle with vertices (1, 2, 3), (3, 0, 1), and (-1, 4, 2) is:

  • A. (1, 2, 2)
  • B. (3, 6, 6)
  • C. (1, 3, 2)
  • D. (2, 2, 2)

26. What is the equation of xz-plane?

  • A. y = 0
  • B. x = 0
  • C. z = 0
  • D. x + z = 0

27. Ratio in which yz-plane divides segment joining (2, 4, 5) and (3, 5, -4) is:

  • A. -2 : 3 (externally)
  • B. 2 : 3 (internally)
  • C. 3 : 2 (internally)
  • D. 1 : 2

28. Length of diagonal of a cuboid with sides a, b, c is:

  • A. √(a² + b² + c²)
  • B. a + b + c
  • C. √(a² + b²)
  • D. 2(ab + bc + ca)

29. Coordinates of point on z-axis at distance 5 from origin are:

  • A. (0, 0, ±5)
  • B. (±5, 0, 0)
  • C. (0, ±5, 0)
  • D. (5, 5, 5)

30. Signs of coordinates in Octant VIII (X O Y' Z') are:

  • A. (+, -, -)
  • B. (-, -, -)
  • C. (+, +, -)
  • D. (-, +, -)

How to use these MCQs

This page contains a chapter-wise objective practice set. Try the questions without checking the answer first, then use the explanation to understand the point you missed. The current page contains 30 questions, so you can practise in smaller sets when you are revising.

Quick revision tip

After the practice set, write down the question numbers you missed and revise only those concepts once more. This makes MCQ practice more useful than repeatedly attempting the same questions without reviewing mistakes.

More for this chapter

Class 11 › Mathematics › Introduction to Three Dimensional Geometry
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