Q. 114.0( 1 Vote )

The net external torque on a system of particles about an axis is zero. Which of the following are compatible with it?
A. The forces may be acting radially from a point on the axis.

B. The forces may be acting on the axis of rotation.

C. The forces may be acting parallel to the axis of rotation.

D. The torque caused by some forces may be equal and opposite to that caused by other forces.

Answer :

As we know that


When forces are acting radially then θ=0. So,


When forces are acting on axis of rotation then r=0. So,


When forces are acting parallel to axis of rotation then its component in plane r and F is 0. Hence F=0. So,


When torques are equal and opposite then net torque is zero.


Hence correct options are a, b, c, d.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Centre of Mass Frame (C-Frame)Centre of Mass Frame (C-Frame)Centre of Mass Frame (C-Frame)59 mins
Angular momentum & its conservation | Getting Exam ReadyAngular momentum & its conservation | Getting Exam ReadyAngular momentum & its conservation | Getting Exam Ready37 mins
Important Questions on TorqueImportant Questions on TorqueImportant Questions on Torque43 mins
Moment of Inertia | Some special casesMoment of Inertia | Some special casesMoment of Inertia | Some special cases40 mins
Interactive Quiz on Moment of InertiaInteractive Quiz on Moment of InertiaInteractive Quiz on Moment of Inertia56 mins
Motion of Centre of MassMotion of Centre of MassMotion of Centre of Mass37 mins
Interactive Quiz | Some important problems of centre of massInteractive Quiz | Some important problems of centre of massInteractive Quiz | Some important problems of centre of mass43 mins
Theorems of perpendicular and parallel axesTheorems of perpendicular and parallel axesTheorems of perpendicular and parallel axes45 mins
Moment of Inertia | Understanding the basicsMoment of Inertia | Understanding the basicsMoment of Inertia | Understanding the basics51 mins
Introduction to Rotation & TorqueIntroduction to Rotation & TorqueIntroduction to Rotation & Torque37 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :