60
MCQ (Single Correct Answer)
The matrix $\left[\begin{array}{ccc}1 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 4\end{array}\right]$ is a
A
identity matrix
B
symmetric matrix
C
skew-symmetric matrix
D
None of these
61
MCQ (Single Correct Answer)
The matrix $\left[\begin{array}{ccc}0 & -5 & 8 \\ 5 & 0 & 12 \\ -8 & -12 & 0\end{array}\right]$ is a
A
diagonal matrix
B
symmetric matrix
C
skew-symmetric matrix
D
scalar matrix
62
MCQ (Single Correct Answer)
If $A$ is matrix of order $m \times n$ and $B$ is a matrix such that $A B^{\prime}$ and $B^{\prime} A$ are both defined, then order of matrix $B$ is
A
$m \times m$
B
$n \times n$
C
$n \times m$
D
$m \times n$
63
MCQ (Single Correct Answer)
If $A$ and $B$ are matrices of same order, then $\left(A B^{\prime}-B A^{\prime}\right)$ is
A
skew-symmetric matrix
B
null matrix
C
symmetric matrix
D
unit matrix
64
MCQ (Single Correct Answer)
If $A$ is a square matrix such that $A^2=I$, then $(A-I)^3+(A+I)^3-7 A$ is equal to
A
$A$
B
$I-A$
C
$I+A$
D
$3 A$