Physics Circle home Student Login

Home›Chapters›Vectors PYQs›Vector Basics, Unit Vectors & Components›Question 3

MHT CET 2026 (18 Apr, Shift 2) · Vector Basics, Unit Vectors & Components

Vector Basics, Unit Vectors & Components question from MHT CET 2026 (18 Apr, Shift 2)

Q3MHT CET 2026 · 18 APR · SHIFT 2Easy

Vector Basics, Unit Vectors & Components

If a unit vector is represented by U⃗=0.9i^−0.2j^+mk^\vec{U} = 0.9\hat{i} - 0.2\hat{j} + m\hat{k}, then the value of m is

Show answer and solution

Answer: (b)

  1. For a unit vector ∣U⃗∣2=1|\vec{U}|^2 = 1.
  2. 0.92+0.22+m2=1⇒0.81+0.04+m2=10.9^2 + 0.2^2 + m^2 = 1 \Rightarrow 0.81 + 0.04 + m^2 = 1
  3. m2=0.15⇒m=0.15m^2 = 0.15 \Rightarrow m = \sqrt{0.15}
  4. So the answer is (b) 0.15\sqrt{0.15}.
Report a mistake

More questions on Vector Basics, Unit Vectors & Components