# ECAT – Mathematics (Matrices & Determinants)

Matrices and Determinants Multiple Choice Questions,the following sample question are from Matrices, Determinants, their properties & key facts.

**Mathematics-Matrices & Determinants Sample Questions**

1. If the order of matrix A is . And the order of B is . Then the order of matrix AB is ?

(A) m × n

(B) n × m

(C) n × p

(D) m × p

2. If A and B are matrices, then which from the following is true ?

(A) A + B ≠ B + A

(B) (A^{t})^{t} ≠ A

(C) AB ≠ BA

(D) all are true

3. What is ‘a’, if

is a singular matrix ?

(A) 5

(B) 6

(C) 7

(D) 8

4. If

then |A| = ?

(A) 2

(B) 3

(C) 4

(D) 5

5. If

then order of matrix A = ?

(A) 2 x 2

(B) 2 x 3

(C) 3 x 2

(D) 3 x 3

**Answers**

**1. A**

**2. C**

**3. D**

**4. B**

**5. B**

6. The number of non-zero rows in an echlon form is called ?

(A) reduced echlon form

(B) rank of a matrix

(C) conjugate of the matrix

(D) co-factor of the matrix

7.

(A) BtAt

(B) AtBt

(C) AB

(D) BA

8. The matrix

is a ?

(A) symmetric

(B) skew-symmetric

(C) hermitian

(D) skew-hermitian

9. If

then |A| = ?

(A) 30

(B) 40

(C) 50

(D) 60

10. The matrix

is a ?

(A) even matrix

(B) odd matrix

(C) scalar matrix

(D) identity matrix

Anwers

6. B

7. A

8. A

9. D

10. C