Easy MCQ +4 / -1 PYQ · JEE Mains 2022

If force $\overrightarrow F = 3\widehat i + 4\widehat j - 2\widehat k$ acts on a particle position vector $2\widehat i + \widehat j + 2\widehat k$ then, the torque about the origin will be :

  1. A $3\widehat i + 4\widehat j - 2\widehat k$
  2. B $- 10\widehat i + 10\widehat j + 5\widehat k$ Correct answer
  3. C $10\widehat i + 5\widehat j - 10\widehat k$
  4. D $10\widehat i + \widehat j - 5\widehat k$

Solution

<p>$\overrightarrow \tau = \overrightarrow r \times \overrightarrow F$</p> <p>$$ = (2\widehat i + \widehat j + 2\widehat k) \times (3\widehat i + 4\widehat j - 2\widehat k)$$</p> <p>$= - 10\widehat i + 10\widehat j + 5\widehat k$</p>

About this question

Subject: Physics · Chapter: Rotational Motion · Topic: Centre of Mass

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