The value of λ for which two vectors 2i ˆ-j ˆ+2k ˆ and 3i ˆ+λj ˆ+k ˆ are perpendicular is

(a) 2                      (b) 4                     (c) 6                     (d) 8

This question is similar to Question-23-Choice-1 CBSE Class 12 Sample Paper for 2023 Boards

The value of λ for which two vectors 2i - j + 2k & 3i + λj + k are - CBSE Class 12 Sample Paper for 2024 Boards

part 2 - Question 16 - CBSE Class 12 Sample Paper for 2024 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

 

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Two vectors 𝑝 ⃗ and 𝑞 ⃗ are perpendicular if their scalar product is zero, i.e. 𝒑 ⃗ . 𝒒 ⃗ = 0 Since 2𝑖 ˆ−𝑗 ˆ+2𝑘 ˆ and 3𝑖 ˆ+𝜆𝑗 ˆ+𝑘 ˆ are perpendicular to each other. Thus, (2𝒊 ̂ − 𝒋 ̂ + 2𝒌 ̂) . (3𝒊 ̂ + ("𝜆" 𝒋) ̂ + 𝒌 ̂) = 0 (2 × 3) + (-1 × 𝜆) + (2 × 1) = 0 6 − 𝜆 + 2 = 0 8 = 𝜆 𝜆 = 8 So, the correct answer is (d)

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 15 years. He provides courses for Maths, Science and Computer Science at Teachoo