Physics 9702 · AS & A Level · Potential difference and power
Potential difference and power — practice question
A potential difference is imposed across two horizontal metal plates separated by $6.0\,\text{mm}$ in a vacuum, as shown in Fig. 7.1. The upper plate is at $-450\,\text{V}$ and the lower plate is earthed. Assume the field between the plates is uniform. A radioactive source releases a $\beta^-$ particle, which passes through a hole in the lower plate and then moves vertically until it reaches the upper plate.
(a(i))[4]
Find the size and direction of the electric force on the $\beta^-$ particle as it moves between the plates.
(a(ii))[2]
Calculate the work done by the electric field on the $\beta^-$ particle as it travels from the lower plate to the upper plate.
(b)[2]
A $\beta^-$ particle leaves the source with a kinetic energy of $3.4 \times 10^{-16}\,\text{J}$. Calculate the speed of emission of the $\beta^-$ particle.
(c(i))[2]
Complete the equation below to show the decay of the neutron.
$^{1}_{0}\text{n} \rightarrow \, ^{0}_{-1}\beta^- + \; \ldots \; + \; \ldots$
(c(ii)-1)[1]
State the particle class that includes neutrons.
(c(ii)-2)[1]
State the particle class that includes $\beta^-$ particles.
Worked solution & mark scheme
This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applies $E = V/d$ or $E = F/Q$” …