2. Question 2: Draw and label a positive and negative charge to make a dipole configuration. Draw the predicted electric field lines, showing the direction with arrows, and also a few equipotential lines.

1. Instead of using two parallel plates, we decide to construct a capacitor from two concentric, conducting spherical shells, as shown in the figure on the right. The inner shell has radius a and charge +Q, and the outer shell has radius b and carries charge -Q. What is the capacitance of this device? [Hint: Compute the difference in voltage between the inner and outer shells by integrating the electric field between the shells in the radial direction.]