Types of matrices - One Line Questions
1.
If A is a symmetric matrix, then A^T = ? —
A
2.
Any matrix A can be expressed as the sum of a symmetric and a skew-symmetric matrix. The symmetric part is given by: —
(A + A^T)/2
3.
Any matrix A can be expressed as the sum of a symmetric and a skew-symmetric matrix. The skew-symmetric part is given by: —
(A - A^T)/2
4.
For a skew-symmetric matrix A, the diagonal elements must be: —
Zero
5.
What is the order of a null matrix if it is also a square matrix? —
nxn
6.
If A is a skew-symmetric matrix, then A^T = ? —
-A
7.
If A is an orthogonal matrix, then A⁻¹ is equal to: —
A^T
8.
A matrix A is orthogonal if: —
A^T A = I
9.
For a symmetric matrix A, the elements satisfy the condition: —
a_ij = a_ji
10.
A triangular matrix is also a diagonal matrix if: —
All its non-diagonal elements are zero
11.
Which type of matrix has only one row? —
Row matrix
12.
A square matrix where all the elements are identical and non-zero is a: —
Scalar matrix
13.
Which of the following is NOT a type of square matrix? —
Row matrix
14.
If A = [[5, 0], [0, 5]], this is an example of a: —
Scalar matrix
15.
In a diagonal matrix, the elements a_ij are zero when: —
i ≠ j
16.
In an upper triangular matrix, the elements a_ij are zero when: —
i > j
17.
In a lower triangular matrix, the elements a_ij are zero when: —
i < j
18.
The identity matrix of order 2x2 is denoted by: —
I₂
19.
A matrix A is idempotent if A² = A. Which of the following is an idempotent matrix? —
Both Identity and Null matrix
20.
A matrix A is involutory if A² = I. Which of the following is an involutory matrix? —
Identity matrix
21.
A square matrix A is called nilpotent of index k if A^k = 0 and A^(k-1) ≠ 0. If k=1, then A is: —
Null matrix
22.
A matrix where all the elements below the main diagonal are zero is a: —
Upper triangular matrix
23.
If A = [[1, 2], [0, 3]], this is an example of a: —
Upper triangular matrix
24.
A matrix of order m x n is rectangular if: —
m ≠ n
25.
A matrix where all the elements are negative is called a: —
Negative matrix
26.
A scalar matrix where the diagonal elements are all 1 is called a: —
Identity matrix
27.
A matrix where all elements are equal is called a: —
Constant matrix
28.
A square matrix A is called periodic if A^k = I for some positive integer k. If k=1, then A is: —
Identity matrix
29.
A matrix where at least one element is non-zero is called a: —
Non-zero matrix
30.
If A = [[0, 0], [0, 0]], this is an example of a: —
Null matrix
31.
A matrix where all the elements are positive is called a: —
Positive matrix
32.
An identity matrix is always a: —
Square matrix
33.
A matrix where the number of rows is equal to the number of columns is known as a: —
Square matrix
34.
A matrix with only one column is called a: —
Column matrix
35.
A matrix of order 1x1 is always a: —
Both Row and Column matrix
36.
A matrix in which all the elements are zero is called a: —
Null matrix
37.
A square matrix where all the non-diagonal elements are zero is termed as a: —
Diagonal matrix
38.
Which type of matrix is both upper triangular and lower triangular? —
Diagonal matrix
39.
If A = [[2, 0], [0, 3]], this is an example of a: —
Diagonal matrix
40.
If A = [[1, 0], [0, 1]], this is an example of a: —
All of the above
41.
A matrix A is called Hermitian if A^θ = A. For a real matrix to be Hermitian, it must be: —
Symmetric
42.
A matrix that remains unchanged after transposition is: —
Symmetric matrix
43.
A matrix A is called skew-Hermitian if A^θ = -A, where A^θ is the conjugate transpose of A. For a real matrix to be skew-Hermitian, it must be: —
Skew-symmetric
44.
A matrix that becomes its negative after transposition is: —
Skew-symmetric matrix
45.
A square matrix is called skew-symmetric if its transpose is equal to: —
The negative of the matrix
46.
A square matrix is called symmetric if its transpose is equal to: —
The matrix itself
47.
Which type of matrix has all diagonal elements equal and all non-diagonal elements zero? —
Scalar matrix
48.
A matrix where all the elements above the main diagonal are zero is a: —
Lower triangular matrix
49.
If A = [[1, 2], [3, 4]], this is an example of a: —
Rectangular matrix
50.
If A = [[1, 0], [2, 3]], this is an example of a: —
Lower triangular matrix