CBSE 2025 · Region 2 · Set 3 · Q20 · 1 mark
Assertion (A) : A $\displaystyle =\operatorname{diag}\left[\begin{array}{lll}3 & 5 & 2\end{array}\right]$ is a scalar matrix of order $\displaystyle 3 \times 3$.
Reason (R) : If a diagonal matrix has all non-zero elements equal, it is known as a scalar matrix.
Official answer
From CBSE’s own marking scheme for this paper.
(D)
Assertion (A) is false but Reason (R) is true.
MatricesTypes of MatricesUnderstandassertion_reasoneasy
More from Matrices
- Let both AB^′ and B^′ A be defined for matrices A and B. If order of A is n × m, then the order of B is:2025 · asked 3×
- Given A=[ ] and B=[ ], find AB. Hence, solve the system of linear equations: OR If A=[ ], then find A^-1.…2025 · asked 3×
- Four friends Abhay, Bina, Chhaya and Devesh were asked to simplify 4 AB+3(AB+BA)-4 BA, where A and B are both…2025 · asked 3×
- Three students, Neha, Rani and Sam go to a market to purchase stationery items. Neha buys 4 pens, 3 notepads…2025 · asked 3×
- If inverse of matrix [ ] is the matrix [ ], then value of λ is:2024 · asked 3×
- If A=[ ] and (3 I+4 A)(3 I-4 A)=x^2 I, then the value (s) x is/are:2023 · asked 3×
- If A=[ ], find A^-1 and use it to solve the following system of equations: -2 y+z=7,2 x-y-z=8, x-2 y=10 OR If…2026 · asked 3×
- What is the total number of possible matrices of order 3 × 3 with each entry as √2 or √3?2025 · asked 3×
CBSE Class 12 Mathematics past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.