Draw lines on Fig. 9.1 to represent this the direction of the field. lines to (b) Fig. 9.2 shows a very small negatively-charged oil drop in the air between a pair of oppos charged horizontal metal plates. The oil drop does not move up or down. oil drop Fig. 9.2 (1) Suggest, in terms of forces, why the oil drop does not move up or down. (ii) Without losing any of its charge, the oil drop begins to evaporate. State and explain what happens to the oil drop.​