Types of Matrices - Practice Questions & MCQ

Equal Matrices: Two matrices are said to be equal if they have the same order and each element of one matrix is equal to the corresponding elements of another matrix or we can say where a is the element of one matrix and b is the element of another matrix.

Square matrix: the square matrix is the matrix in which the number of rows = number of the columns. So a matrix  is said to be a square matrix when m = n.

E.g.

Rectangular matrix: Rectangular matrix is the matrix in which is the number of rows ≠ number of columns.

So a matrix   is said to be a rectangular matrix when m ≠ n.

E.g.

Null matrix/ Zero Matrix: A matrix whose all elements are 0, is called a null matrix. 

Eg, , 

Diagonal matrix: A square matrix is said to be a diagonal matrix, if all its elements except the diagonal elements are zero. 

So, a matrix  is a diagonal matrix if   and m = n.

E.g

A diagonal matrix of order n x n having diagonal elements as d₁, d₂, d₃ ………, d_n is denoted by 

For example

Scalar matrix: A diagonal matrix whose all the diagonal elements are equal is called a scalar matrix.

Where c is not equal to 0 

Unit or Identity Matrix: A diagonal matrix of order n whose all the diagonal elements are equal to one is called an identity matrix of order n. It is represented as .

So, a square matrix is Identity matrix if 

For example,