(a) Figure 11.1 shows two point clusters of charge situated in free space placed on a line that is called the x-axis. The first, with a positive charge of Q1 = +8e, is at the origin. The second, with a negative charge of Q2 = -4e, is to the right at a distance equal to 0.2 m. (i) What is the magnitude of the force between them? (ii) Where would you expect to find the position of zero electric field: to the left of Q1 , between Q1 and Q2 or to the right of Q2 ? Briefly explain your choice and then work out the exact position. (b) The electron in a hydrogen atom orbits the proton at a radius of 5.3x10^(-11) m. (i) What is the proton's electric field strength at the position of the electron? (ii) What is the magnitude of the electric force on the electron?