Question

(c) Sketch an equipotential surface at a distance r from a point charge q, and state the magnitude of the work done in moving a small test charge along that surface. The membrane that surrounds a certain type of living cell has a surface area of 4.1 x 10¯9 m 2 and a thickness of 1.5 x 10¯8 m. Assume that the sides of the membrane behave like a pair of equipotential surfaces, with a material of dielectric constant 5.2 between them. If the potential on the outer surface of the membrane is +86.9 mV greater than that on the inside surface, determine how much charge resides on the outside surface. [7 marks]

Answer 1

POTEn 2. rn V 86.9m woAk done moving Toft aYe arg e Y10 Volume TA t 109