Calculate electric force and acceleration in electric fields, then predict charged-particle direction, speed and trajectory between plates or around charges.
This question is in two parts. Part 1 is about photoelectricity. Part 2 is about electrical and magnetic force fields.
Part 1 Photoelectricity
(b) The diagram shows a pair of horizontal metal plates. Electrons can be deflected vertically using an electric field between the plates.
Label, on the diagram, the polarity of the metal plates which would cause an electron positioned between the plates to accelerate upwards.