So my task says

A particle with mass $m$ moves freely through space and there is no electromagnetic field. At moment $t = 0$ a uniform magnetic field is turned on with field strength $B$, and direction perpendicular to the velocity of the particle. At moment $t = T$ the field is turned off. What is the deviation of the direction of the particle that happened while uniform field was turned on?

In textbook it says:
To solve this I must assume that the magnetic force changes the particle's direction, not magnitude. So I will get $F_{cp}$ (centripetal force) $= F_{mg}$ (force of the magnetic field).

But what I don't understand is how can magnetic force make particle move in a circle (direction of the magnetic field), if by applying the right hand rule, the force of the magnetic field is perpendicular to the direction of the magnetic field?

  • $\begingroup$ it is not moving in the direction of the magnetic field. $\endgroup$ – anna v Jun 25 '19 at 6:35

As you mentioned, the force experienced by a moving charged particle in a magnetic field is perpendicular to both the magnetic field and the particle's velocity. This force causes the direction of the velocity of the particle to change, so the direction of the force in the next moment also changes. When you draw this out, the force always towards a point in the circle. enter image description here

| cite | improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.