Physics 9702 · AS & A Level · Electric field of a point charge
Electric field of a point charge — practice question
As shown in Fig. 6.1, two identical metal spheres A and B are both positively charged, and the distance between their centres is 24\,\text{cm}. Fig. 6.2 plots how the electric field strength E produced by the two spheres changes with distance x from the centre of A along the line joining the centres.
(a)[1]
State the radius of each sphere.
(b)[3]
Sphere A carries a charge of $3.6 \times 10^{-9}\,\text{C}$. Find the charge $Q_{B}$ on sphere B, assuming that spheres A and B may be treated as point charges at their centres. Show your working.
(c(i))[2]
Sphere B is taken away. Use the information from (b) to find the electric potential at the surface of sphere A.
(c(ii))[2]
Calculate the capacitance of sphere A in this situation.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “2.0 cm” …