(a) State what is meant by electric potential at a point. (b) The centres of two charged metal spheres A and B are separated by a distance of 44.0 cm, as shown in [Figure 7.1]. Point P is a distance x from the centre of sphere A. The variation with distance x of the electric potential V at point P is shown in [Figure 7.2]. (i) Use [Figure 7.2] to state and explain whether the two spheres have charges of the same, or opposite, sign. (ii) A positively-charged particle is at rest on the surface of sphere A. The particle moves freely from the surface of sphere A to the surface of sphere B. 1. Describe qualitatively the variation, if any, with distance x of the speed of the particle as it moves from x = 12 cm to x = 25 cm passes through x = 26 cm moves from x = 27 cm to x = 31 cm reaches x = 32 cm 2. The particle has charge 3.2 × 10⁻¹⁹ C and mass 6.6 × 10⁻²⁷ kg. Calculate the maximum speed of the particle. speed = .............................................................. ms⁻¹