Introduction To Three Dimensional Geometry CBSE Questions & Answers

Introduction To Three Dimensional Geometry

This is Mathematics Class 11 Introduction to Three Dimensional Geometry CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The distance of the point ( 3, 4, 5) from X- axis is
  • A
    \(\sqrt {34} \)
  • B
    \(\sqrt {41} \)
    Correct
  • C
    5
  • D
    3
2
The direction cosines of X -axis are
  • A
    \(<\) 0 , 1 , 1 \(>\)
  • B
    \(<\) 0 , 0 , 1 \(>\)
  • C
    \(<\) 0 , 1 , 0 \(>\)
  • D
    \(<\) 1 , 0 , 0 \(>\)
    Correct
3
The medians of a triangle are concurrent at the point called
  • A
    circumcentre
  • B
    orthocentre
  • C
    centroid
    Correct
  • D
    incentre
4
The direction cosines of any normal to the XY plane are
  • A
    \(<\) 0 , 1 , 0 \(>\)
  • B
    \(<\) 1 , 0 , 0 \(>\)
  • C
    \(<\) 1 , 1 , 0 \(>\)
  • D
    \(<\) 0 , 0 , 1 \(>\)
    Correct
5
How many lines through the origin make equal angles with the coordinate axes ?
  • A
    1
  • B
    4
    Correct
  • C
    2
  • D
    8
6
he numbers 3, 4 , 5 can be
  • A
    coordinates of a point in the plane x + y – z = 0
  • B
    coordinates of a point on the line y = 4 , z = 0
  • C
    direction numbers of a line in space
    Correct
  • D
    direction cosines of a line in space
7
f the direction cosines of a straight line are \(<\) k , k , k \(>\) , then
  • A
    k = 1
  • B
    0 \(<\) k \(<\) 1
  • C
    \(k = {1 \over {\sqrt {3} }}ork = - {1 \over {\sqrt 3 }}\)
    Correct
  • D
    k \(>\) 0
8
wo lines, which do not lie in the same plane, are called
  • A
    coincident
  • B
    skew
    Correct
  • C
    parallel
  • D
    intersecting
9
The radius of the sphere through the points ( 4 ,3 , 0 ) , ( 0 , 4 , 3 ) ,( 0 , 5 , 0 ) and ( 4 , 0 , 3 ) is
  • A
    5
    Correct
  • B
    7/ 5
  • C
    5/ 7
  • D
    7
10
The points ( 4,7 ,8) ,( 2, 3,4 ),( - 1 , -2 , 1 ) and (1 , 2, 5 ) are the vertices of a
  • A
    rectangle
  • B
    rhombus
  • C
    parallelogram
    Correct
  • D
    square
11
The equation xy = 0 in three dimensional space represents
  • A
    a pair of straight lines
  • B
    a pair of parallel lines
  • C
    a pair of planes at right angles
    Correct
  • D
    a plane
12
The graph of the equation \({x^2} + {y^2} = 0\) in the three dimensional space is
  • A
    Z - axis
    Correct
  • B
    Y - axis
  • C
    X - axis
  • D
    XY – plane
13
In three dimensional space, locus of the equation \({x^2} + {z^2} = 0{x^2} + {z^2} = 0\) is
  • A
    a degenerate sphere
  • B
    a degenerate circle
  • C
    empty set
  • D
    y - axis
    Correct
14
The distance of the point ( x , y , z ) from the XY –plane is
  • A
    z
  • B
    y
  • C
    \({\text{I z I}}\)
    Correct
  • D
    x
15
The angle between the lines x = 1 , y = 2 and y = - 1 , z = 0 is
  • A
    \({0^0}\)
  • B
    \({30^0}\)
  • C
    \({90^0}\)
    Correct
  • D
    \({60^0}\)