NCERT MCQ CLASS-12 CHAPTER-3 | MATH NCERT MCQ | MATRICES | EDUGROWN

In This Post we are  providing Chapter-3 R NCERT MCQ for Class 12 Math which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON MATRICES

Question 1.
If A = [a_ij]_{m × n} is a square matrix, if:
(a) m < n
(b) m > n
(c) m = n
(d) None of these.

Answer: (c) m = n

Question 2.
Which of the given values of x and y make the following pair of matrices equal:
[3x+7y+152−3x] [08y−24]
(a) x = –13, y = 7
(b) Not possible to find
(c) y = 7, x = –23
(d) x = –13, y = –23

Answer: (b) Not possible to find

Question 3.
The number of all possible matrices of order 3 × 3 with each entry 0 or 1 is
(a) 27
(b) 18
(c) 81
(d) 512.Answer

Answer: (d) 512.

Assume X, Y, Z, W and P are matrices of order 2 × n, 3 × 1, 2 × p, n × 3 and p × k respectively. Now answer the following (4-5):
Question 4.
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.

Answer: (a) k = 3, p = n

Question 5.
If n =p, then the order of the matrix 7X – 5Z is:
(a) p × 2
(b) 2 × n
(c) n × 3
(d) p × n.

Answer: (b) 2 × n

Question 6.
If A, B are symmetric matrices of same order, then AB – BA is a
(a) Skew-symmetric matrix
(b) Symmetric matrix
(c) Zero matrix
(d) Identity matrix.

Answer: (a) Skew-symmetric matrix

Question 7.
If A = [cosα−sinαsinαcosα] then A + A’ = I, the value of α is
(a) π6
(b) π3
(c) π
(d) 3π2

Answer: (a) π6

Question 8.
Matrices A and B will be inverse of each other only if:
(a) AB = BA
(b) AB – BA = O
(c) AB = O, BA = I
(d) AB = BA = I.

Answer: (d) AB = BA = I.

Question 9.
If A = [αγβ−α] is such that A² = I, then
(a) 1 + α² + ßγ = 0
(b) 1 – α² + ßγ = 0
(c) 1 – α² – ßγ = 0
(d) 1 + α² – ßγ = 0

Answer: (c) 1 – α² – ßγ = 0

Question 10.
If a matrix is both symmetric and skew- symmetric matrix, then:
(a) A is a diagonal matrix
(b) A is a zero matrix
(c) A is a square matrix
(d) None of these.

Answer: (b) A is a zero matrix

Question 11.
If A is a square matrix such that A² = A, then (I + A)³ – 7A is equal to :
(a) A
(b) I – A
(c) I
(d) 3A.

Answer: (c) I

Question 12.
The matrix A = ⎡⎣⎢005050500⎤⎦⎥ is a
(a) scalar matrix
(b) diagonal matrix
(c) unit matrix
(d) square matrix.

Answer: (d) square matrix.

Question 13.
If matrix A = [a_ij]_2×2
where a_ij = 1 if i ≠ j = 0 if i = j,
(a) I
(b) A
(c) O
(d) None of these

Answer: (a) I

Question 14.

then A – B is equal to
(a) 1
(b) O
(c) 21

Answer: (c) 21

Question 15.
If A is a 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.

Answer: (d) m × n.

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