Question

A square matrix $\left(a_{ij}\right)$ in which $a_{ij}=0$ for $i\ne j$ and $a_{ij}=k$(constant) for $i=j$ is a

• A. unit matrix
• B. scalar matrix
• C. null matrix
• D. none these

Answer 1

The correct option is B scalar matrix

In the given matrix all the elements other than the diagonal are zero and diagonal elements are equal to $k.$

We know that a diagonal matrix is a matrix in which the entries outside the main diagonal are all zero and a diagonal matrix with all its main diagonal entries equal is a scalar matrix.

Hence, B will be code answer.