6.4 Exercise 27

Two $10 \text{cm} \times 10 \text{cm}$ pieces of aluminum foil of thickness 0.1 mm face each other with a separation of 5 mm. One of the foils has a charge of $+\text{30} \mu \text{C}$ and the other has $− 30 \mu \text{C}$. (a) Find the charge density at all surfaces, i.e., on those facing each other and those facing away. (b) Find the electric field between the plates near the center assuming planar symmetry.