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Capacitors. AP Physics. Capacitors. What are they? A device that stores electrical potential energy by storing charge. How is that useful? Capacitors are used when a lot of energy is needed quickly (brief burst of power) What does a capacitor consist of?
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Capacitors AP Physics
Capacitors What are they? A device that stores electrical potential energy by storing charge. How is that useful? Capacitors are used when a lot of energy is needed quickly (brief burst of power) What does a capacitor consist of? Any two conducting objects separated by a vacuum or other type of insulating material.
Capacitance The ratio of the magnitude of the charge Q on either conductor to the magnitude of the potential difference V between the conductors. The Farad is named after the English physicist/chemist Michael Faraday who had many valuable contributions in the field of electromagnetism.
Parallel Plate Capacitors Capacitor with two parallel plates of area A and separation distance d. The electric field between the plates is uniform. The capacitance of a parallel plate capacitor is: Notice: Capacitance of a parallel plate capacitor is not dependent on the charge of the capacitor, but rather on the dimensions of the plates and the separation.
Parallel Plate Capacitor A parallel plate capacitor has a capacitance of 1.0 F, and the plates are 1 mm apart. What is the area of the plates? This is about 10 km per side…bigger than Manhattan!! Common values for capacitance are microfarads (1 μF = 10-6 F) and picofarads (1 pF = 10-12 F)
Capacitor Energy The oppositely charged plates of a capacitor are comparable to a stretched spring or an object lifted to a higher gravitational potential energy. The energy stored in a capacitor is: