Activity 2: The electric quadrupole, revisited Figure 2A shows the electric quadrupole from last week again. Figure 2B has an additional element, a metal sphere in the center of the quadrupole. A 4 +q 1 -q -q 3 a - +9 2 -------- B +q -9 Figure 2: The electric quadrupole. In B), a metal sphere is located in the center of the charge arrangement. +q Preparation questions 1. Draw the electric field lines for both situations into the two figures. Your drawings must contain: a. Field lines in the inner region and in the outer region of the quadrupole (separated by the dashed lines). b. The directions of the field vectors must be indicated (using arrow tips). 2. The drawings you made should be different in some respects. Write a paragraph discussing the differences between the two situations. Your discussion must at least include the following aspects: a. Do field lines start or end in different locations? b. Do field vectors point in different directions anywhere in the drawings? c. Are there any areas in either drawing in which there are no field lines? d. Why are the differences present - what is their physical meaning?