Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AIIMS 2013
Exam
AIIMS
Year
2013
Subject
Physics
Chapter
Rotational Motion

AIIMS 2013 · Physics · Rotational Motion

Given that force (5 i +7 j -3 k ) N acts on a particle at position...

Given that force (5i^+7j^−3k^)N(5 \hat{i}+7 \hat{j}-3 \hat{k}) \mathrm{N} acts on a particle at position (i^+j^−k^)m(\hat{i}+\hat{j}-\hat{k}) \mathrm{m}. Find torque of this force on the particle about origin.

Options

  1. A4i^−2j^+2k^4 \hat{i}-2 \hat{j}+2 \hat{k}
  2. B2i^−3j^+4k^2 \hat{i}-3 \hat{j}+4 \hat{k}
  3. C5i^−2j^+3k^5 \hat{i}-2 \hat{j}+3 \hat{k}
  4. D6i^−4j^+4k^6 \hat{i}-4 \hat{j}+4 \hat{k}

Correct answer

A. 4i^−2j^+2k^4 \hat{i}-2 \hat{j}+2 \hat{k}

Step-by-step solution

Torque, τ⃗=r⃗×F⃗\vec{\tau}=\vec{r} \times \vec{F} =(i^+j^−k^)×(5i^+7j^−3k^)=(\hat{i}+\hat{j}-\hat{k}) \times(5 \hat{i}+7 \hat{j}-3 \hat{k}) =i^(−3+7)−j^(−3+5)+k^(7−5)=\hat{i}(-3+7)-\hat{j}(-3+5)+\hat{k}(7-5) τ⃗=4i^−2j^+2k^\vec{\tau}=4 \hat{i}-2 \hat{j}+2 \hat{k}
Practice Rotational Motion on Quantrex Academy →

More from Rotational Motion

A solid sphere A of radius R and mass M is attached at a point to a smaller solid sphere… NEET 2026The angular speed of a flywheel is increased from 600 rpm to 1200 rpm in 10 s. The number… NEET 2026A thin wire of length ' L ' and linear mass density ' m ' is bent into a circular ring… NEET 2026A thin horizontal disc is rotating about a vertical axis passing through its fixed centre… NEET 2026The Sun rotates around its centre once in 27 days. What will be the period of revolution… NEET 2025A sphere of radius R is cut from a larger solid sphere of radius 2 R as shown in the… NEET 2025The radius of gyration of a solid sphere of mass 5 kg about X Y is 5 m as shown in… NEET 2024A wheel of a bullock cart is rolling on a level road as shown in the figure below. If its… NEET 2024 Full Rotational Motion list All AIIMS PYQs