help please (1 Viewer)

[Arithela]

why does a charge entering a magnetic field at 90 degrees travel in the arc of a circle?

 

[Forbidden.]

why does a charge entering a magnetic field at 90 degrees travel in the arc of a circle?

You know F = qvB but it's actually F_B = qv x B

Remember the right hand rule ?
The three components in the right hand rule for this formula are F, v and B hence why I've made the bold to indicate them as vectors.

The charged particle moves in a circle because the magnetic force is perpendicular to v and B with constant magnitude qvB.
(Then the magnetic force is also equal to the centripetal force because the components are very similar)

Image below