(i) The electric field at a point 10 cm away from a charge P as in FIGURE 1 is 2.7 x 10 NC-1. Determine the charge of P. (ii) a charge Q is placed 10 cm away from charge P. When charge Q is moved horizontally to the right to a position 5 cm from its initial position, there is a 0.54 J change in its electric potential energy of the system. What is the charge of Q?

(iii) Sketch the electric force vectors on charge P and Q.

(iv) If charge Q is again moved horizontally to the right to a new position, and the electric force on it is -4.05 N; how far apart is charge Q from charge P?

(b) Two oppositely charged parallel plates are held 2 mm apart. A 4 x 107 of work is needed to move a 2 C point charge from one plate to the other. Calculate the electric field between the plates.