NDA MATHS QUESTION BANK

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  1. If^ are the angles which a line


makes with positive x, y, z axes
respectively, what is the value of cos α



  • cos β + cos γ?
    (a) 1 (b) -1 (c) 2 (d) 3



  1. Given, the sphere
    and the two
    points A(1, -1, 2) and B(2, -3, 4). Which
    one of the following is correct?
    (a) A, B are inside the sphere (b) A, B
    are outside the sphere (c) A is inside
    the sphere and B is outside the sphere
    (d) A is outside the sphere and B is
    inside the sphere

  2. For what value of k are the lines


and
perpendicular to each other?
(a) -2 (b) -1 (c)1 (d) 2



  1. What is the sum of direction
    cosines of a line which is equally
    inclined to the positive directions of the


axes?
(a) 3 (b) 1 (c) √ (d) 3/√


  1. What is the angle between the line
    6x = 4y = 3z and the plane 3x + 2y – 3z=
    4?
    (a) 0 (b) π/6 (c) π/3 (d) π/2

  2. A line makes 45 with positive x-
    axis and makes equal angles with
    positive y, z axes, respectively. What is
    the sum of the three angles which the
    line makes with positive x, y and z axes?
    (a) 180 (b) 165 (c) 150 (d) 135

  3. If the centre of the sphere


is (1/2, -1, -1/2), what is the value of
b?
(a) 1 (b) -1 (c) 2 (d) - 2


  1. What is the length of the
    perpendicular from the origin to the
    plane ax + by + √ z= 1?
    (a) 1/(ab) (b) 1/(a + b) (c) a + b (d)
    ab


VECTOR ALGEBRA



  1. Projection of 2 ̂ ̂ ̂ along
    ̂ ̂ ̂ is:


(a) 2/√ (b) 1/√ (c) √ (d) 2√



  1. Area of parallelogram ABCD, when


⃗⃗⃗⃗⃗^ = ̂ ̂ ̂ and ⃗⃗⃗⃗⃗⃗^ ̂ ̂is:
(a) 1 sq unit (b) 6 sq units (c) 3 sq
units
(d) none of these



  1. Area of parallelogram ABCD, when
    ⃗⃗⃗⃗⃗^ = ̂ ̂ ̂ and ⃗⃗⃗⃗⃗⃗^ ̂ ̂ + ̂ is:
    (a) √ sq units (b) 2√ sq units (c)
    √^
    sq units (d) none of these^

  2. ̂ ( ̂) ̂ ( ̂) ̂ (
    ̂) is always equal to:
    (a) (b) - (c) 2 (d) - 2

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