Actually, is there an equivalent approximation trick for log ? I'm stuck because I have to consolidate 1/r and log( f(r) ). Should I use Taylor series ?
Homework Statement
I'm trying to prove that Electric field away from a line segment of charge, is equivalent to the field away from a point charge, provided I observe from far enough.
Homework Equations
Ignoring all the constants:
potential_line = log( (sqrt(r^2 + a^2) + a) /...
imagine a charge placed inside a closed conducting shell (a hollow metal box or sphere)
Feynman says:
- no static distribution of charges inside a closed conductor can produce any fields outside. The fields on the two sides of a closed conducting shell are completely independent.
but...