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Question 15 (OR 1st Question) - CBSE Class 12 Sample Paper for 2020 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at Dec. 16, 2024 by Teachoo

The magnitude of projection of  (2i − j + k ) on (i − 2j + 2k ) is _______

Transcript

Question 15 (OR 1st Question) The magnitude of projection of (2𝑖 ̂ − 𝑗 ̂ + 𝑘 ̂) on (𝑖 ̂ − 2𝑗 ̂ + 2𝑘 ̂) is _______ Projection of vector 𝒂 ⃗ on 𝒃 ⃗ = 𝟏/|𝒃 ⃗ | (𝒂 ⃗. 𝒃 ⃗) Let 𝑎 ⃗ = 2𝑖 ̂ – 𝑗 ̂ + 𝑘 ̂ 𝑏 ⃗ = 𝑖 ̂ – 2𝑗 ̂ + 2𝑘 ̂ (𝒂 ⃗ . 𝒃 ⃗) = (2 × 1) + (–1 × −2) + (1 × 2) = 2 + 2 + 2 = 6 Magnitude of 𝑏 ⃗ = √(12+(−2)2+22) |𝑏 ⃗ | = √(1+4+4) |𝑏 ⃗ | = √9 |𝑏 ⃗ | = 3 Projection of 𝑎 ⃗ on 𝑏 ⃗ = 1/|𝑏 ⃗ | (𝑎 ⃗. 𝑏 ⃗) = 1/3 × 6 = 2 ∴ Magnitude of projection is 2 units
  1. Class 12
  2. Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

    3. CBSE Class 12 Sample Paper for 2020 Boards

    CBSE Class 12 Sample Paper for 2019 Boards →
CBSE Class 12 Sample Paper for 2019 Boards →
Class 12
Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

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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 14 years. He provides courses for Maths, Science and Computer Science at Teachoo