aklec02 - 2 Static Fields and Potentials When sources have...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
2 Static Fields and Potentials When sources have no time variation, or when ) ( and ) ( r J J r The resulting fields have no time variation either, and they are functions of position r only: ) ( ), ( ), ( ), ( r H H r B B r D D r E E If we replace the time derivative by zero, static equations are obtained. 0 0 0 t 0 J H E B D D J H B E B D t t Assuming free-space, D = E and B = H are valid. Under static conditions, the fields (and equations) are decoupled. E and H can exist without the other.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Electrostatics Electrostatic fields are observed when charges are at rest, or static with respect to the observer. Governing equations in free-space are: E D E D 0 0 Static E field is curl-free, i.e. there is no vector or rotating source for static E . As a result, it is conservative. Mathematically the line integral is path independent, or closed line integral of it is identically zero. Utilizing the vector identity static E can be expressed as where ) , , ( z y x V V is the electrostatic potential. So that a unique potential, (or potential difference wrt a reference) is assigned to every point in space. field scalar any for 0 ) ( C S d d 0 theorem Stokes' Apply 0 0 l E S E E V  E
Background image of page 2
Magnetostatics Static magnetic fields are observed when charges are moving with constant velocity with respect to the observer. Governing equations in free-space are: 0 0 H B J H B Utilizing the vector identity F F field any vector for 0 ) ( static B can be expressed as A B where ) , , ( z y x A A is the magnetic vector potential.
Background image of page 3

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

View Full DocumentRight Arrow Icon
Field Calculations The diagram below demonstrates the two possible approaches to field calculations. The simpler approach is chosen for the particular problem at hand. Usually potential approach is
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 13

aklec02 - 2 Static Fields and Potentials When sources have...

This preview shows document pages 1 - 5. Sign up to view the full document.

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