"An electron beam is equivilent to an electric current, but without the wire. It can bla bla bla.... In this diagram, the magnetic field is at right angles to the electron beam, so the beam is deflected."
This is what my book says... but how come the electrons go down (srry for bad quality). If u use Flemingooo's left hand rule, the current is ur middle finger(so points to the left [direction of electrons]), the field is ur second finger (pointing into the paper[direction of magnetic field]) and so ur thumb will be pointing up, which shows how the electrons will be deflected...How come they show it going down?