14_1?Capacitance Feb/19/2016 M.?Burkardt?? NMSU?? PHYS?214?? Spring?2016 1 Phys214 Electricity & Magnetism Capacitance DEMO Materials: ? 2 sheets of aluminum foil, 1 sheet paper to make a capacitor ? Wimshurst machine ? Parallel plate capacitor ? voltmeter Lecture Outline ? Energy in the electric field ? What is a capacitor? ? Calculating Capacitance (for different geometries of capacitors) What is a Capacitor? Two conducting ?plates? (isolated electrically from each other) with opposite sign charge of the same magnitude |Q|. ? ? ?? ?? ? ? ? ? ? ? ? ? ? ? cross-section of a long cylindrical capacitor side view of a parallel-plate capacitor Charge Separation and Energy Stored in Electric Field What is a capacitor? A capacitor stores charge and energy.