Magnetic force on a moving point charge is perpendicular to its velocity and the magnetic field.
Difficulty
Intermediate
Read time
5 min
Prerequisites
Basic algebra, consistent units, and the stated model assumptions
Source
OpenStax, College Physics 2e, §22.4 (Paul Peter Urone and Roger Hinrichs)OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example. The textbook section reference was corrected.
Magnetic force on a moving point charge is perpendicular to its velocity and the magnetic field. Its magnitude vanishes for motion parallel to the field, and its direction reverses for a negative charge.
| Symbol | Meaning | Units |
|---|---|---|
| Magnetic force magnitude | ||
| Electric charge | ||
| Particle speed | ||
| Magnetic Field | ||
| Angle between velocity and magnetic field |
Find magnetic-force magnitude on a moving charge.
Compare force for different velocity-field angles.
A charge of magnitude 0.00200 C moves at 100 m/s perpendicular to a 0.500 T magnetic field. Find the magnetic-force magnitude.
OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example. The textbook section reference was corrected.
Assumptions
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