PHY213_Chapter16_Sec6to10

PHY213_Chapter16_Sec - Chapter 16 Electrical Energy And Capacitance Capacitance Sections 6 10 General Physics Capacitance A capacitor is a device

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 16 Electrical Energy And Capacitance
Background image of page 1

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

View Full DocumentRight Arrow Icon
General Physics Capacitance Sections 6 – 10
Background image of page 2
General Physics Capacitance A capacitor is a device used in a variety of electric circuits The capacitance, C, of a capacitor is defined as the ratio of the magnitude of the charge on either conductor (plate) to the magnitude of the potential difference between the conductors (plates) Units: Farad (F) 1 F = 1 C / V A Farad is very large Often will see μF or pF V Q C MU30T18
Background image of page 3

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

View Full DocumentRight Arrow Icon
General Physics Parallel-Plate Capacitor The capacitance of a device depends on the geometric arrangement of the conductors For a parallel-plate capacitor whose plates are separated by air: d A Q Q d Q Ed Q V Q C 0 0 / ε σ = = = = capacitor plate parallel a for d A C o =
Background image of page 4
General Physics Parallel-Plate Capacitor, Example The capacitor consists of two parallel plates Each have area A They are separated by a distance d The plates carry equal and opposite charges When connected to the battery, charge is pulled off one plate and transferred to the other plate Transfer stops when V cap = V battery Active Figure: Parallel Plate Capacitors EX16.6
Background image of page 5

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

View Full DocumentRight Arrow Icon
General Physics Electric Field in a Parallel-Plate Capacitor The electric field between the plates is uniform Near the center Nonuniform near the edges The field may be taken as constant throughout the region between the plates
Background image of page 6
General Physics Applications of Capacitors – Camera Flash The flash attachment on a camera uses a capacitor A battery is used to charge the capacitor The energy stored in the capacitor is released when the button is pushed to take a picture The charge is delivered very quickly, illuminating the subject when more light is needed
Background image of page 7

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

View Full DocumentRight Arrow Icon
General Physics Applications of Capacitors – Computers Computers use capacitors in many ways Some keyboards use capacitors at the bases of the keys When the key is pressed, the capacitor spacing decreases and the capacitance increases The key is recognized by the change in capacitance
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/25/2009 for the course PHY 213 taught by Professor Cao during the Summer '08 term at Kentucky.

Page1 / 24

PHY213_Chapter16_Sec - Chapter 16 Electrical Energy And Capacitance Capacitance Sections 6 10 General Physics Capacitance A capacitor is a device

This preview shows document pages 1 - 9. Sign up to view the full document.

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