The Magnus Effect is a phenomenon associated with the generation of
- ADrag on a stationary cylinder.
- BCavitation in hydraulic turbines.
- CLift on a rotating cylinder or sphere moving through a fluid.Correct
- DWater hammer in long pipelines.
Solution
Concept
Magnus Effect
Explanation
When an object like a cylinder or ball spins while moving through a fluid (like air or water), it creates a difference in fluid speed and pressure on opposite sides. This pressure difference generates a sideways force known as "lift," which causes the object's path to curve.
Shortcut
To remember the Magnus Effect, use the memory rule "Spin creates Lift": - Spin = Sideways Force: When an object rotates (spins) while moving through a fluid, it creates a pressure difference that generates Lift (causing the path to curve).
Common mistake
A common mistake is selecting Option A by confusing the Magnus Effect with standard boundary layer drag on a stationary object, or confusing it with pressure surge phenomena like water hammer (Option D). Students often overlook that the Magnus Effect specifically requires rotation (spin) of the body to generate a sideways lift force perpendicular to the direction of motion.
Correct answer: C) Lift on a rotating cylinder or sphere moving through a fluid.