# Multiple choice (Matrix)

Choose and write the correct option in the following question:(Class 12 matrix multiple choice question)

1.) If Then is equal to

(a)

(b)

(c)

(d)

2.) If , then if the value of α is

(a) π/6                          (b) π/3

(c) π                               (d) 3π/2

3.)If A and B are square matrices of the same order , then (A + B)(A – B) is equal to

(a)                         (b)

(c)     (d)

4.) Total number of possible matrices of order 3×3 with each entry 2 or 0 is

(a)  9                         (b) 27

(c) 81                         (d) 512

5.) The matrix is a

(a) Diagonal matrix               (b) Symmetric matrix

(c) Skew symmetric matrix    (d) Scalar matrix

Assume X, Y, Z, W and P are matrices of order 2×n,3×k, 2×p, n×3 and p×k respectively. Choose the correct option in (6) and (7)

6.) The restriction on n, k and p so that PY + WY willbe defined are

(a) k = 3, p = n                      (b) k is arbitrary, p = 2

(c) p is arbitrary, k = 3        (d) k = 2, p = 3

7.) If n = p then the order of the matrix 7X – 5Z is

(a) p×2                          (b) 2×n

(c) n×3                           (d) p×n

8.) If , Then the value of x and y is

(a) x = 3, y = 1                 (b) x = 2, y = 3

(c) x = 2, y = 3                 (d) x = 3, y = 3

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

(a) m×m                           (b) n×n

(c) n×m                            (d) m×n

10.) 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

11.) If is such that , then

(a) I + α² + βγ = 0         (b) I – α² + βγ = 0

(c) I – α² – βγ = 0            (d) I + α² – βγ = 0

12.) A matrix is defined by

The number of elements in A which are more than 5 is

(a) 3                  (b) 4

(c) 5                   (d) 6

13.) If  , then (wher a∈ N) equals

(a)

(b)

(c)

(d)

14.) If A is a square matrix such that A² = I, then is equal to

(a) A                     (b) I – A

(c) I + A                (d) 3A

15.) If the matrix AB is zero, then

(a) It is not necessary that either A = O or B = O

(b) A = O or B = O

(c) A = O and B = O

(d) All the statement are wrong

16.) If and , then

(a) Only AB is defined                 (b) Only BA is defined

(c) AB and BA both are defined   (d) AB and BA are not defined.

17.) If A and B are symmetric matrices of the same order, then (AB’- BA’) is a

(a) Skew symmetric matrix               (b) Null matrix

(c) Symmetric matrix                          (d) None of these

18.) The  matrix is

(a) A Skew symmetric matrix           (b) Null matrix

(c) A diagonal matrix                           (d) An upper triangular matrix

19.) 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

20.) If and A = A’, then

(a)  x = 0, y = 5                 (b)  x + y = 5

(c)  x = y                             (d) None of these