Physics 9702 · AS & A Level · Potential difference and power
Potential difference and power — practice question
A uniform electric field is set up between two parallel metal plates. The electric field strength is $1.4 \times 10^{4}\,\text{N C}^{-1}$. The potential difference across the plates is $350\,\text{V}$.
(a)[2]
Calculate how far apart the plates are.
(b(i))[3]
A nucleus with mass $8.3 \times 10^{-27}\,\text{kg}$ is placed in the electric field. The force on the nucleus is $6.7 \times 10^{-15}\,\text{N}$. Calculate the charge on the nucleus in terms of $e$, where $e$ represents the elementary charge.
(b(ii))[1]
Calculate the nucleus mass, in u.
(b(iii))[1]
Use your answers in (b)(i) and (b)(ii) to work out how many neutrons are in the nucleus.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “From the relationship, $E = \dfrac{V}{d}$” …