NDA MATHS QUESTION BANK

38. If n≠3k and 1, are the cube roots of

unity, then |
| has the value:

(a) 0 (b) (c) (d) 1

39. If X= 0 1 and I is a 2×2 identity matrix,

then equals to wwhich one of the
following?
(a) –I (b) -2X (c) 2X (d) 4X

40. The value of the determinant

|
| is:

(a) 2(10!11!) (b) 2(10!13!) (c) 2(10!11!12!)
(d) 2(11!12!13!)

41. If 0 1
    0 1 = 0 1 , then which one of

the following is correct?
(a) x=5, y=14 (b) x=-5, y=14 (c) x=-5, y=- 14
(d) x=5, y=- 14

42. l, m, n are and terms of a GP, all

positive, then |
| equals:

(a)-1 (b) 2 (c) 1 (d) 0

43. The matrix A= 0 1 satisfies which one of

the following polynomial equations?
(a) +3A+2I=0 (b) +3A-2I=0 (c) - 3A-
2I=0 (d) - 3A+2I=0

44. If f(x)=

|
( ) ( )
( ) ( )( ) ( ) ( )

|,

then f(100) is equal to:
(a) 0 (b) 1 (c) 100 (d) - 100

45. If AB= 0 1 and A= 0 1 , then what is

the value of the determinant of the matrix B?
(a) 4 (b) -6 (c) - (d) - 28

46. If |
    |=0 and x, y, z are all

different, then the value of xyz, is:

(a) (x-y)(y-z)(z-x) (b) 0 (c) 1 (d) - 1

47. If A is any 2×2 matrix such that
    0 1 0 1
    then what is A equal to?
    (a) 0 1 (b) 0 1 (c) 0 1 (d)
    0 1


48. The value of the determinant

|

| is equal to:

(a) x+y (b) x-y (c) 1 (d) 0

49. If A is a 3×3 matrix such that | | then
    what is A (adj A) equal to?
    (a) [
    ] (b) [
    ]

(c) [

] (d) Cannot be determined,

as data is insufficient

50. If x= cy+bz, y= az+cx, z= bx+ay and x, y, z
    are not all zero , then:
    (a) (b)
    (c) (d)


51. If A= [
    ] where x, y, z are

distinct. What is | |

(a) 0 (b) (c) (x-y)(y-z)(z-x)

(d) xyz

52. If A be an n×n matrix and c any scalar, then
    | | is equal to:
    (a) | | (b) | | (c) nc| | (d) c| |