Lorentz force
Lorentz force is an interactive experiment in Electric & Magnetic Fields, a free simulation from StudyFi Lab that runs right in your browser.
A charged particle moving in a magnetic field feels the Lorentz force F = q·v·B at right angles to its velocity. The force only turns the motion and never changes the speed, so the particle goes round a circle of radius r = m·v/(|q|·B) with period T = 2π·m/(|q|·B). An added electric field E pushes the opposite way: at the speed v = E/B the two forces balance and the particle flies straight (a velocity selector).
Try this: Double the speed — the radius doubles, but the period T stays the same.
Frequently asked questions
What does the “Lorentz force” experiment show?
A charged particle moving in a magnetic field feels the Lorentz force F = q·v·B at right angles to its velocity. The force only turns the motion and never changes the speed, so the particle goes round a circle of radius r = m·v/(|q|·B) with period T = 2π·m/(|q|·B). An added electric field E pushes the opposite way: at the speed v = E/B the two forces balance and the particle flies straight (a velocity selector).
How do I try “Lorentz force”?
Double the speed — the radius doubles, but the period T stays the same.
Studying for a test?
Upload your notes and StudyFi turns them into flashcards, tests and podcasts.