1 / 6

A Crash Course in Electric Fields

A Crash Course in Electric Fields. By Leah Chernoff. What are Electric Fields? What do they do?. An E-field (E) exerts a force on charged particles in space. F=qE, when F is force and q is a charged particle.

anoki
Télécharger la présentation

A Crash Course in Electric Fields

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. A Crash Course in Electric Fields By Leah Chernoff

  2. What are Electric Fields? What do they do? • An E-field (E) exerts a force on charged particles in space. F=qE, when F is force and q is a charged particle. • E-fields are created by voltage differentials between points in space. E= -∆V/R, when ∆V is the voltage difference over a certain distance R.

  3. Why Does Voltage Affect the E-Field? • For a point charge Q, V= kQ/R • For a point charge Q, E= kQ/R2 • So, E= -dV/dr (the negative accounts for the fact that electric fields are directed in the direction opposite to the direction of increasing voltage; that is, fields go from high voltage to low voltage.)

  4. Field Lines • THEY CAN NEVER CROSS (like in Ghostbusters) • Negative charges always feel force opposite of the electric field • Double the field lines means twice as strong • Positive E-field --> lines go out; lines go in for negative E-field • Confused? Check out this cool simulation! http://www.vias.org/simulations/simusoft_efield.html

  5. Example Problems There is a 10V voltage difference over 25 m. What is the magnitude of the electric field? ANSWER: E = ∆V/R; 10/25 = .4 V/m What is the force on a particle with charge -3 C in this field? ANSWER: F = qE F = -3(.4) = 1.2 N in the opposite direction of the field

  6. Useful Equations and Facts • Units: N/C or V/m • E = -dV/dr = kQ/R2 • F = qE • Another cool simulation website: http://www.its.caltech.edu/~phys1/java/phys1/EField/EField.html

More Related