
#1
Apr1410, 08:31 PM

P: 4

question
For a plane wave of the form E(z,t)=Ee^i(kzwt) and B(z,t)=Ee^(kz)*e^i(kzwt) write down the timeaveraged ohmic heating loss per unit volume for any z. 2. Relevant equations J=[tex]\sigma[/tex]E Maxwell's equations for linear media 3. The attempt at a solution not sure where to start, i need a nudge 



#2
Apr1510, 07:38 PM

P: 2,070

You know E, and you gave us the equation for J, so you know J. Do you know how to find the Ohmic heating, given J and E?




#3
Apr1510, 10:09 PM

P: 4

yea i figured it out. you take the dot product of J and E.




#4
Apr1610, 12:06 AM

P: 4

ohmic heating in a conductor
ok now i have Re([tex]\sigma[/tex]) ((Ee^(kz)e^i(kz[tex]\omega[/tex]t))^2)/2
is this right? do i need to simplify if im going to integrate with respect to z? 



#5
Apr1610, 06:06 AM

P: 2,070

Careful with the Re(). Remember Re(A) Re(B) is not equal to Re(AB) since there are cross terms. Here it looks like you assumed Re(E^2) = (Re(E))^2, which it's not.




#6
Apr1610, 08:10 PM

P: 4

so is what i have already wrong?



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