Lec05 - • The capacitance of a capacitor increases by a factor κ when a piece of insulating dielectric material is inserted between the plates

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Capacitor and Capacitance A capacitor is a device which stores charge. It consists of two conductors (of any shape) placed near each other. A battery is used to charge a capacitor. The battery in effect removes charge from one conductor and deposits it on the other. When charged, each conductor carries a charge of the same magnitude, but opposite in sign. The magnitude of the charge q on each conductor is directly proportional to the potential difference V between the conductors: Therefore where C is the capacitance. The unit of C is Farad (=Coul/Volt) In general , the value of capacitance C depends on geometric construction of the capacitor. For a parallel plate capacitor of area A and plate spacing d V q CV q = d A C 0 ε = ) / 10 85 . 8 4 1 ( 2 2 12 0 Nm C k × = = π A (area) d + Battery +q -q V + + + + +
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Capacitors and Dielectric
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: • The capacitance of a capacitor increases by a factor κ when a piece of insulating ( dielectric ) material is inserted between the plates. – Where C is the capacitance before the dielectric is inserted, and is the dielectric constant of the material – This increase is due to induced surface charge on the dielectric. • For a parallel plate capacitor with dielectric: • Energy is stored in a capacitor when charged. – The stored energy is equal to the amount of work done by the battery in transfer charge from one plate to the other. – For a capacitor with charge magnitude q and potential difference V between the plates C C = d A C κε = d A (area) dielectric C q CV qV Energy 2 2 1 2 1 2 2 = = =...
View Full Document

This note was uploaded on 12/06/2011 for the course PHYSICS 111&112 taught by Professor Unknown during the Spring '11 term at Ohio State.

Page1 / 2

Lec05 - • The capacitance of a capacitor increases by a factor κ when a piece of insulating dielectric material is inserted between the plates

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online