1 / 20

Charge

Static Electricity Principles of Physics. Charge. Charge is the ability to attract or repel  Q (large charges) q (small charges) Units: coulombs (C) Types of charge: positive or negative  neutral → no charge. Charge. Charged particles: Electron – around nucleus

brygid
Download Presentation

Charge

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. Static Electricity Principles of Physics Charge

  2. Charge is the ability to attract or repel  Q (large charges) q (small charges) Units: coulombs (C) Types of charge: positive or negative  neutral → no charge Charge

  3. Charged particles: Electron – around nucleus Charge = -1 elementary charge (-1e) Proton – in nucleus Charge = +1 elementary charge (+1e) Charge

  4. Amount of charge a particle has is proportional to the number of excess electrons or protons Q = Ne Q = charge (C) = q  N = number of excess charges e = elementary charge = charge of a proton when + = charge of an electron when - Magnitude of charge

  5. Example: A charged sphere has an excess of 15 protons. What is the charge of the sphere? Q = Ne = +15e Magnitude of charge

  6. Like charges REPEL Unlike charges ATTRACT

  7. A force exists between all charged bodies • When the charges are like the force causes them to move away • When the charges are unlike the force causes them to toward each other • According to Newton’s 3rd law, if one charged body acts on another, the other acts back on it with the same force Electrostatic Force F1 +Q F1 -q F2 F2 +q

  8. A force exists between all charged bodies • Inverse relationship between force and distance • Force increases when distance decreases • Force decreases when distance increases • Direct relationship between force and charge • Force increases when charge increases • Force decreases when charge decreases Electrostatic Force

  9. Conductors: metals lots of loosely connected, easily moved electrons Insulators: plastic, ceramics Tightly bound electrons Semiconductors: Silicon, Germanium Semi-tight electrons – more movement at high temps Conductivity affected by doping (adding materials that help control conduction) Materials

  10. Source (donator) or sink (acceptor) of an infinite amount of charge without significantly changing its own charge Examples: Earth You Ground

  11. Methods • Inducing a charge (Induction) • Neutral objects can act charged when placed near a charged object • Charge by Conduction • Charging by touch • Permanently charge by induction • Charging by touching to ground Transfer of charge

  12. When a negatively charged object is brought near a neutral object, electrons move away from it The object attract because the unlike charges are near When a positively charge object is brought near a neutral object, electrons in the neutral object move toward it The objects attract because unlike charges are near Inducing a charge + + + + + + + + + + + + + + + + + + + -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- + + + + + + + + + +

  13. Why does the balloon stick to the wall? Balloon (rubbed over hair) Wall (Neutral)

  14. The charges in the wall separate

  15. Charge transfers directly from one object to another • Results in equal charge on all objects • Charges distribute evenly between objects charge by conduction

  16. Example: A sphere with a charge of -4e touches a sphere with a charge of -6e. What is their charge after they separate again? Together they have: After they separate they -6e + -4e = -10e each have: -10e/2 = -5e charge by conduction

  17. Example: A sphere with a charge of -4e touches a sphere with a charge of +8e. What is their charge after they separate again? Together they have: After they separate they +8e + -4e = +4e each have: +4e/2 = +2e charge by conduction

  18. Charging by touching to ground Permanently Charging by Induction

  19. Transfer of opposite charge, but same amount Example: If charged object has a charge of +24e, then object charged by induction will have -24e. Permanently Charging by Induction

More Related