NCERT Class 12 Chapter 3 Maths Matrices MCQ

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1. If A and B are symmetric matrices of the same order, then

A. AB is a symmetric matrix

B. A – Bis askew-symmetric matrix

C. AB + BA is a symmetric matrix

D. AB – BA is a symmetric matrix

2. The number of 3 × 3 non-singular matrices, with four entries as 1 and all other entries as 0, is:

A. less than 4

B. 5

C. 6

D. at least 7

A. 6

B. 3

C. 2

D. 0

4. If A and B are two matrices of the order 3 × m and 3 × n, respectively, and m = n, then the order of matrix (5A – 2B) is

A. m × 3

B. 3 × 3

C. m × n

D. 3 × n

5. If A=[32x+3x−1x+2] is a symmetric matrix, then x =

A. 4

B. 3

C. -4

D. -3

A. 1

B. 4

C. 2

D. 3

7. If A is a square matrix, then A – A’ is a

A. diagonal matrix

B. skew-symmetric matrix

C. symmetric matrix

D. none of these

8. If A is matrix of order m × n and B is a matrix such that AB’ and B’A are both defined, then order of matrix B is

A. m × m

B. n × n

C. n × m

D. m × n

9. For what real value of y will matrix A be equal to matrix B, where

CBSE Class12 Maths Matrices (9Q)

A. 1, 3

B. No real value

C. 1/3, 1/2

D. 2 and 3

10. If A is any square matrix, then which of the following is skew-symmetric?

A. A + A^T

B. A – A^T

C. AA^T

D. A^TA

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11. If a matrix A is both symmetric and skew symmetric then matrix A is

A. a scalar matrix

B. a diagonal matrix

C. a zero matrix of order n × n

D. a rectangular matrix

12. [5]is a scalar matrix of order

A. 2

B. 5

C. 0

D. 1

13.

A. α = a² + b², β = ab

B. α = a² + b², β = 2ab

C. α = a² + b², β = a² – b²

D. α = 2ab, β = a² + b²

14. If A and B are matrices of same order, then (AB’ – BA’) is a

A. skew symmetric matrix

B. null matrix

C. symmetric matrix

D. unit matrix

15.

A. The number of Men in BPO II

B. The number of Women in BPO II

C. The number of Women in BPO I

D. The number of Men in BPO I

16. If A = ⎡⎣⎢100210x01⎤⎦⎥ and B = ⎡⎣⎢100−210y01⎤⎦⎥ and AB = I3, then x + y equals

A. 0

B. -1

C. 2

D. None of these

17. If a matrix A is both symmetric and skew-symmetric, then

A. A is a diagonal matrix

B. A is a zero matrix

C. A is a scalar matrix

D. A is a square matrix

18.

A. an identity matrix

B. a zero matrix

C. a Scalar m

D. diagonal matrix.

19. If A = [1221] and f(x) = (1 + x) (1 – x), then f(a) is CBSE Class12 Maths Matrices (19Q)

A. (a)

B. (b)

C. (c)

D. (d)

20. If A is a square matrix such that A² = I, then (A – I)³ + (A + I)³ – 7A is equal to

A. A

B. I – A

C. I + A

D. 3 A

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21.

A. 2 x 5

B. 2 x 2

C. 5 x 2

D. 5 x 5

22. If A = [1334] and A2 – KA – 5I = 0, then K =

A. 5

B. 3

C. 7

D. None of these

23. The restrictions on n, k and p so that PY + WY will be defined are

A. k = 3, p = n

B. k is arbitrary, p = 2

C. p is arbitrary

D. k = 2,p = 3

24. What is the element in the 2^nd row and 1^st column of a 2 x 2 Matrix A= [ a_ij], such that a = (i + 3) (j - 1)

A. 0

B. 4

C. -5

D. 5

25.

A. (a)

B. (b)

C. (c)

D. (d)