Paritian

Physics

Lorentz Force Calculator

Magnetic force on a moving charge, the radius it curves through and its cyclotron frequency.

Results

Force 0.50000000 N
Radius 3.34524e-15 m
Frequency 4.75765e+19 Hz
Time 2.10188e-20 s

What this tool does

The force is always at right angles to the motion, so it bends a charged particle into a circle without ever speeding it up — that is the whole principle of a cyclotron and of the aurora. A charge moving straight along the field lines feels nothing at all, which is why the angle matters. The default mass is that of a proton.

Formula

F = q × v × B × sin θ ; r = m v ÷ (q B)

Variables

SymbolMeaningUnit
qElectric chargeµC
vSpeedm/s
bMagnetic fieldT
anAngle°
mMasskg
FForceN
RRadiusm
FCFrequencyHz
PRTimes

Worked example

  • Electric charge1 µC
  • Speed1,000,000 m/s
  • Magnetic field0.5 T
  • Angle90 °
  • Mass1.67262e-27 kg
  • Force0.50000000 N
  • Radius3.34524e-15 m
  • Frequency4.75765e+19 Hz
  • Time2.10188e-20 s

Limitations

  • The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.
  • The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.