Capacitance: (speaking in regards to a demo capacitor built from an aluminum and mylar sheet, as well as a couple of electrical leads)
a) How does the shape of the foil affect the capacitance? Would it still be a capacitor if the foil and mylar took on a different shape; say for example if the top sheet of foil were crumpled into a ball?
b) Discuss the effects of Ac€A?fringingAc€?? of the fields. Why is C= ErE0 (A/d) an approximation to the capacitance of a parallel plate capacitor?