In a vacuum, two similar solid metal spheres A and B, each with radius $R$, have their centres separated by $D$, as shown in Fig. 6.1. Sphere A carries charge $+Q$ and sphere B carries charge $+q$, with $+Q$ greater than $+q$. A movable point $P$ lies on the straight line joining the centres of the two spheres. Point $P$ is at a distance $x$ from the centre of sphere A.
(a(i))[2]
State what the electric potential at a point means.
(a(ii))[2]
State the relationship between electric potential at a point and electric field strength at the point.
(b)[4]
In Fig. 6.1, two similar solid metal spheres A and B, each of radius $R$, are placed in a vacuum with their centres separated by a distance $D$. The charge $+Q$ on sphere A is greater than the charge $+q$ on sphere B. A movable point P lies on the line joining the two centres. Point P is at a distance $x$ from the centre of sphere A. On Fig. 6.2, sketch a graph to show how the electric potential $V$ varies with $x$ between the centres of the two spheres.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Work done divided by charge” …