Jee Advanced
Matrices And Determinants
JEE Advanced 2024 Paper 1 Online
MCQ+3 / -12024
Let $\alpha$ and $\beta$ be the distinct roots of the equation $x^2+x-1=0$. Consider the set $T=\{1, \alpha, \beta\}$. For a $3 \times 3$ matrix $M=\left(a_{i j}\right)_{3 \times 3}$, define $R_i=a_{i 1}+a_{i 2}+a_{i 3}$ and $C_j=a_{1 j}+a_{2 j}+a_{3 j}$ for $i=1,2,3$ and $j=1,2,3$.
Match each entry in List-I to the correct entry in List-II.
table {
width: 100%;
border-collapse: collapse;
}
th {
background-color: #1E90FF;
color: white;
}
th, td {
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The correct option is
Match each entry in List-I to the correct entry in List-II.
table {
width: 100%;
border-collapse: collapse;
}
th {
background-color: #1E90FF;
color: white;
}
th, td {
border: 1px solid lightgrey;
padding: 8px;
text-align: left;
}
| List-I | List-II |
|---|---|
| (P) The number of matrices $ M = (a_{ij})_{3x3} $ with all entries in $ T $ such that $ R_i = C_j = 0 $ for all $ i, j $, is | (1) 1 |
| (Q) The number of symmetric matrices $ M = (a_{ij})_{3x3} $ with all entries in $ T $ such that $ C_j = 0 $ for all $ j $, is | (2) 12 |
| (R) Let $ M = (a_{ij})_{3x3} $ be a skew symmetric matrix such that $ a_{ij} \in T $ for $ i > j $. Then the number of elements in the set $ \left\{ \begin{pmatrix} x \\ y \\ z \end{pmatrix} : x, y, z \in \mathbb{R}, M \begin{pmatrix} x \\ y \\ z \end{pmatrix} = \begin{pmatrix} a_{12} \\ 0 \\ a_{13} \end{pmatrix} \right\} $ is | (3) infinite |
| (S) Let $ M = (a_{ij})_{3x3} $ be a matrix with all entries in $ T $ such that $ R_i = 0 $ for all $ i $. Then the absolute value of the determinant of $ M $ is | (4) 6 |
The correct option is
