NDA MATHS QUESTION BANK

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  1. If Ѳ is the angle between the


vectors and ⃗^ , such that | ⃗^ |


| ⃗^ |, then Ѳ is:


(a) 0 (b) 45 (c) 120 (d) 180



  1. If , ⃗^ , are three mutually
    perpendicular vectors each of unit
    magnitude, then what is the magnitude


of ⃗^?


(a) 3 (b) 1 (c) √ (d) 1/3



  1. ⃗⃗⃗^ are vectors of length 3, 4 and


5 respectively such that is


perpendicular to ( ⃗^ ), ⃗^ to ( )


and to ( ⃗^ ). What is the


magnitude of the vector ⃗^?


(a) 12 (b) 2√ (c) 5√ (d) 50




  1. If | ⃗^ |
    = k | ⃗^ |
    | |^ | |^ , then
    what is the value of k?
    (a) 1 (b) 2 (c) 0 (d) - 1




  2. If α, β and γ are distinct non-
    negative real numbers such that the
    vectors ̂ ̂ ̂ ̂ ̂ and
    β ̂ ̂ ̂ are coplanar, then which
    one of the following is correct?




(a) (b) β =^ (c) β = (d)


α= 1, β= 0, γ= 1



  1. If ⃗^ are the position vectors of
    corners A, B, C of a parallelogram
    ABCD, then what is the position vector
    of the corner D?


(a) ⃗^ (b) ⃗^ (c)


⃗^ (d) - ⃗^


35. If two unit vectors and make an
angle^ with each other, what is the
magnitude of?
(a) 0 (b) √ (c) 1 (d) √^

36. What are the values of x for which
the two vectors ( ) ̂ ( ) ̂
̂ and 2 ̂ ̂ ̂ are orthogonal?
(a) No real value of x (b) x=^ and x= - 1
(c) x= - and x= 1 (d) x= -1 and x= 2

37. A particle is acted upon by
following forces:
(i) 2 ̂ ̂ ̂ (ii) - 5 ̂ ̂ ̂ and
(iii) 3 ̂ ̂
In which plane does it move?
(a) x-y plane (b) y-z plane (c) z-x plane
(d) Any arbitrary plane
38. If ⃗⃗⃗ , ⃗⃗⃗ ⃗⃗⃗ are the position vectors
of three collinear points and scalars m
and n exist such that ⃗⃗⃗ ⃗⃗⃗ ⃗⃗⃗ ,
then what is the value of (m + n)?
(a) 0 (b) 1 (c) -1 (d) 2


  1. A force m ̂ ̂ ̂ acts on a point
    and so the point moves from (20, 3m,



  1. to (0, 0, 7). If the work done by the
    force is -48 units, what is the value of
    m?
    (a) 5 (b) 3 (c) 2 (d) 1


41. If a and b are two vectors such that
a.b= 0 and a × b= 0, which one of the
following is correct?
(a) a is parallel to b (b) a is
perpendicular to b (c) Either a or b is a
null vector (d) None of the above
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