10th class Mathematics, Chapter 3: Matrices and Determinants MCQs

1. If [[a + 2], [3]] = [[7], [3]], then a =

1. (A) 3
2. (B) 5 ✓
3. (C) 6
4. (D) 7

2. A = [[3, 5, 0]] is a ______ matrix.

1. (A) row ✓
2. (B) square
3. (C) column
4. (D) null

3. B = [[2], [3]] is a ______ matrix.

1. (A) identity
2. (B) square
3. (C) row
4. (D) column ✓

4. M = [[1, 0, 0], [0, 1, 0], [0, 0, 1]] is a/an ______ matrix.

1. (A) rectangular
2. (B) identity ✓
3. (C) column
4. (D) row

5. If Aᵗ = −A, then A is ______ matrix.

1. (A) symmetric
2. (B) row
3. (C) rectangular
4. (D) skew-symmetric ✓

6. If A = [[3, 4]], B = [[7, 8]], then A + B =

1. (A) [[21, 32]]
2. (B) [[24, 28]]
3. (C) [[10, 12]] ✓
4. (D) [[11, 11]]

7. If A = [[3, 4]], B = [[7, 8]], then B − A =

1. (A) [[10, 12]]
2. (B) [[11, 11]]
3. (C) [[4, 4]] ✓
4. (D) [[−4, −4]]

8. What is the additive inverse of the matrix [[3], [4]]?

1. (A) [[−3], [4]]
2. (B) [[−3], [−4]] ✓
3. (C) [[3], [4]]
4. (D) [[−1], [1]]

9. If A = [[3, 1, 3], [2, 0, 2]], then the order of Aᵗ is:

1. (A) 3-by-2 ✓
2. (B) 2-by-3
3. (C) 3-by-3
4. (D) 2-by-2

10. |[[3, 1], [0, 4]]| =

1. (A) 11
2. (B) 12 ✓
3. (C) 13
4. (D) −11

11. A matrix having 3 rows and 4 columns is of order:

1. (A) 3-by-4 ✓
2. (B) 4-by-3
3. (C) 12
4. (D) 7

12. The number of elements in a 3-by-4 matrix is:

1. (A) 4
2. (B) 12 ✓
3. (C) 7
4. (D) 34

13. The entries of a matrix written in a horizontal line form a:

1. (A) order
2. (B) row ✓
3. (C) column
4. (D) diagonal

14. The word "matrix" was first used by:

1. (A) Euclid
2. (B) James Joseph Sylvester ✓
3. (C) Gabriel Cramer
4. (D) Jean Argand

15. A matrix having only one row is called a:

1. (A) null matrix
2. (B) row matrix ✓
3. (C) column matrix
4. (D) square matrix

16. A matrix having only one column is called a:

1. (A) column matrix ✓
2. (B) row matrix
3. (C) identity matrix
4. (D) scalar matrix

17. A matrix in which all entries are zero is called a:

1. (A) scalar matrix
2. (B) diagonal matrix
3. (C) null (zero) matrix ✓
4. (D) unit matrix

18. A matrix in which the number of rows equals the number of columns is called a:

1. (A) rectangular matrix
2. (B) row matrix
3. (C) column matrix
4. (D) square matrix ✓

19. The matrix [[1, 0], [0, 1]] is called:

1. (A) a null matrix
2. (B) a rectangular matrix
3. (C) a skew-symmetric matrix
4. (D) an identity (unit) matrix ✓

20. The matrix [[5, 0], [0, 5]] is:

1. (A) a column matrix
2. (B) a scalar matrix ✓
3. (C) an identity matrix
4. (D) a null matrix