CBSE Class 12 Sample Paper for 2024 Boards

CBSE Class 12 Sample Paper for 2023 Boards →
Maths Class 12
Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Question 13 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at August 14, 2026 by

Given that A is a square matrix of order 3 and |A|=- 2 , then |adj( 2 A)| is equal to

a) -2^6                 (b) +4                 (c) -2^8                (d) 2^8

-lock-

This question is similar to Question 5 Choice 2 CBSE Class 12 Sample Paper for 2021 Boards

Given A is a square matrix of order 3 and |A| = 2, then |adj(2A)| is - CBSE Class 12 Sample Paper for 2024 Boards

part 2 - Question 13 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

-endlock-

Remove Ads
Teachoo · Class 12 Explore Class 12

Transcript

We know that |𝒂𝒅𝒋 𝑨| = |𝑨|^(𝒏−𝟏) where n is the order of determinant ∴|𝒂𝒅𝒋 𝟐𝑨| = |𝟐𝑨|^(𝒏−𝟏) Given Order = n = 3 Now, our equation becomes |𝒂𝒅𝒋 𝟐𝑨| = |𝟐𝑨|^(𝟑−𝟏) |𝑎𝑑𝑗 2𝐴| = |2A|^2 Using property: |𝐤𝑨|=𝒌^𝒏 |𝑨|, Where n is the order of matrix |𝑎𝑑𝑗 2𝐴| = (〖𝟐^𝟑 |𝑨|)〗^𝟐 |𝑎𝑑𝑗 2𝐴| = 〖〖〖(2〗^3)〗^2 |A|〗^2 |𝒂𝒅𝒋 𝟐𝑨| = 𝟐^𝟔 〖(−𝟐)〗^𝟐 |𝑎𝑑𝑗 2𝐴| = 2^6 〖(2)〗^2 |𝒂𝒅𝒋 𝟐𝑨| = 𝟐^𝟖 So, the correct answer is (d)

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh is an IIT Kanpur graduate and has been teaching for 16+ years. At Teachoo, he breaks down Maths, Science and Computer Science into simple steps so students understand concepts deeply and score with confidence.

Many students prefer Teachoo Black for a smooth, ad-free learning experience.