A $\beta^{-}$ particle emitted by a radioactive source is moving through a vacuum with kinetic energy $460\,\text{eV}$. It enters a uniform electric field at right angles and then follows the route shown in Fig. 7.1.
(a)[1]
The electric field lies in the plane of the paper. On Fig. 7.1, add an arrow to indicate the direction of the electric field.
(b)[3]
Determine the speed of the $\beta^{-}$ particle before it enters the electric field.
(c)[2]
Other $\beta^{-}$ particles from the same radioactive source move outside the electric field along the same incident path as the one shown in Fig. 7.1. State and explain briefly whether these $\beta^{-}$ particles will all take the same path inside the electric field.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “an arrow directed vertically down the page” …