1 / 14

Electrical Energy and Capacitance Physics - Chapter 18

Electrical Energy and Capacitance Physics - Chapter 18. Ch. 18-1 (Pages 666-669) I. Electrical Energy & Electric Force. Electrical potential energy - PE associated with an object due to position relative to an electric force. Results from interactions of 2 objects’ charges.

brittany-lynch
Download Presentation

Electrical Energy and Capacitance Physics - Chapter 18

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electrical Energy and Capacitance Physics - Chapter 18

  2. Ch. 18-1 (Pages 666-669) I. Electrical Energy & Electric Force • Electrical potential energy - PE associated with an object due to position relative to an electric force. • Results from interactions of 2 objects’ charges

  3. ΔPE electric change in electric potential energy (final minus initial) • Factors determining PE electric 1. Charge 2. Strength of electric field 3. Position in the direction of the field

  4. PE electric = -q E d d = displacement from ref. point q = charge E = electric field strength

  5. PE electric= Kc (q1q2) r r = distance between charges in meters Kc=8.99 x 109 N(m2/C2) (pairs of charges) Reference point assumed to be infinity Homework : Page 669 #1-4

  6. 18-2 Potential difference (p.670-675) • Electric potential - electric potential energy of a charged particle in an electric field (divided by its charge) • Electric potential (V) = electric potential energy charge of the particle V = PE electric q

  7. V is measured in volts 1 volt = 1 J/C • Potential difference- change in electrical potential energy (V) *only changes in electric potential are significant and important • ΔV = PE electric q • ΔV Measured in volts (V) = 1 J/coulomb

  8. ΔV measures the change in energy per unit of charge • A potential difference within a battery causes charge to move • ex.  12 Volt car battery -positive terminal has electric potential of 12 V -negative terminal has electric potential of 0 V • positive terminal has a higher electric potential then the negative terminal

  9. As 1 coulomb of charge moves from negative to the positive terminal the battery does work on the charge to increase the PE electric of the charge to 12 J of electric potential energy • Each coulomb of charge that leaves the battery would have 12 J of energy • This energy is given up to the parts of the device which is run from the battery

  10. 18-3 Capacitance • Capacitor - a device used in electrical circuits to store charge • A storehouse of charge • Stores positive and negative charges separately

  11. Parallel-plate-capacitor-two metal plates separated by a small distance • Connected to the 2 terminals of a battery (once charged, battery removed) • Charge is removed from one plate and accumulates on another

  12. Capacitance- the ability of a conductor to store energy in the form of electrically separated charges •  Ratio of net charge on each plate to potential difference

  13. SI unit is the farad (F) = coulomb/volt • Capacitance depends on the size, shape, and materials of the capacitor • Larger plates = more storage of energy • Materials between plates can change capacitance

  14. Charged capacitors release energy rapidly •  Ex. – camera flash, computer keyboard

More Related