Subject: Applied Physics 2

Topic: Motion Of Charged Particles In Electric And Magnetic Fields

Difficulty: Medium

consider two plates with length ‘l’ and separated by a distance ‘d’. The upper plate is having positive charge and the lower plate is having negative charge,Initially electrons travel in x direction with velocity $u_x$ .As soon it enters the field, electron being negatively charged experiences acceleration towards the positive plate.

After time t, electron traverses distance x in the horizontal direction.

Let Y be the vertical displacement at this time.

x = v t .........................(1)

y = ut + 1/2 a $t^2$ ...........................(2)

u = 0

Therefore, y = 1/2 (eE/m$v^2$) $x^2$. y = k $x^2$ This is equation of parabola. so the trajectory of electron is a parabola.