Chapter 5.5, Problem 2bT

B. Suppose the plates are discharged, then held a distance D apart and connected to a battery. (Ignore the fringing fields near the plate edges.)

1. Write expressions for the following quantities in terms of the given variables. Explain your reasoning in each case.

• the potential difference $\Delta V$ between the plates

• the electric field at points 1,2,3, and 4

• the charge density on each plate

2. The right plate is moved to the left. Describe how each of the following quantities changes (if at all). Explain.

•the potential difference $\Delta V$ between the plates

• the electric field both outside and between the plates

• the charge density on each plate

3. Write expressions for the following quantities in terms of $V_o$ and d (the flew distance between the plates).

• the magnitude of the electric field between the plates

• the charge density on each plate

4. Find $\frac{Q}{\Delta V}$ (the ratio of the net charge on one plate w the potential difference between the plates).

How, if at all, would this ratio change if the voltage of the battery was $2V_o$ ?