Edges of the dielectric act as a second pair of

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: d in the absence of an electric field Dielectrics – An Atomic View, cont • An external electric field is applied • This produces a torque on the molecules • The molecules partially align with the electric field Dielectrics – An Atomic View, final • An external field can polarize the dielectric whether the molecules are polar or nonpolar • The charged edges of the dielectric act as a second pair of plates producing an induced electric field in the direction opposite the original electric field The result of polarization Table of Some Dielectric Values V for a Uniformly Charged Sphere • A solid sphere of radius R and total charge Q • For r > R, • For r < R, V for a Uniformly Charged Sphere, Graph • The curve for VD is for the potential inside the curve – It is parabolic – It joins smoothly with the curve for VB • The curve for VB is for the potential outside the sphere Problem Solving Strategies – Electric Potentials • Conceptualize – Think about the charges or the charge distribution – Image the type of potential they would create • This establishes a mental representation – Use any symmetry in the arrangement of the charges to help you visualize the potential Problem Solving Strategies – Electric Potentials • Categorize – Individual charges or a distribution? • Analyze – – – – – Scalar, so no components Superposition principle is algebraic sum Signs are important Changes in potential are what is important The point where V = 0 is arbitrary • But usually at a point infinitely far from the charges Problem Solving Strategies – Electric Potentials, cont • Analyze, cont – For a group of individual charges, use the superposition principle – For a continuous charge distribution, integrate over the entire distribution – If is known, the line integral of can be evaluated Problem Solving Strategies...
View Full Document

This note was uploaded on 02/03/2010 for the course NEUROSCI 101A taught by Professor Scheibell during the Winter '10 term at UCLA.

Ask a homework question - tutors are online