Q46 / 160 · TS EAMCET 2020 (11 Sep Shift 2) · Mathematics
$A$ is a singular matrix of order five. $B$ is another matrix having the $\operatorname{rank} \rho(B)$ equal to the rank $\rho(A)$ and $B$ has a non-zero minor of order 3. Then which one of the following is true?
- A$B$ is a $4 \times 4$ matrix
- B$\rho(A)=\rho(B)=4$, irrespective of the order of $B$
- Correct answerC$\rho(A)=\rho(B)=3$, when all the fourth order minors of $A$ are zero
- D$|B|=0$
Solution
Given that, Rank of matrix $A=$ rank of matrix $B$
$f(A)=f(B) \text { and } f(B)=3$
$\therefore$ Order of matrix $B \geq$ Rank of matrix $B$.
Hence, the correct answer is option: 'C'.