Key relationship
τ = rF sinθ = F × perpendicular distance.
Physics · Class 11
Move the force lever
Torque measures the turning effect of a force. Only its component perpendicular to the lever turns the body. A force along the lever produces zero torque even when its magnitude is large.
Open the interactive experiment →Move the force lever
திருப்புவிசை நெம்புகோலுக்கு செங்குத்தான விசைக் கூறைப் பொறுத்தது. நெம்புகோல் வழியே செயல்படும் விசையின் திருப்புவிசை பூஜ்யம்.
Key notes, relationships and model limits
Remember
Torque measures the turning effect of a force. Only its component perpendicular to the lever turns the body. A force along the lever produces zero torque even when its magnitude is large.
Common trap
A larger force does not guarantee a larger torque when the lever arm or angle changes.
Model limits
One force on a rigid lever about a fixed pivot. Positive torque follows the chosen turning sense; angle is between radius and force.
What you will learn
Predict torque from force magnitude, angle and pivot distance.
Try the experiment
Try both scenarios, change one control, and predict the result before checking the graph and readouts.
Think of it this way
Change one input while keeping the others fixed, as you would in a controlled experiment.
Worked example
At 30°, the same force gives τ = 2×10×0.5 = 10 N·m; at 0° it gives zero.
Why this matters
The model connects move the force lever with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
What torque does a 10 N perpendicular force at 2 m produce?
- 10 N·m
- 20 N·m
- 40 N·m
Read the explanation
τ = 2×10×sin90° = 20 N·m.
Course connection: Class XI Chapter 6. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.