8.2.4 Reflection and Transmission at Normal Incidence

8.2.4 of Griffith's Introduction to Electrodynamics 2nd Ed
EM Plane Waves approaching a boundary between two non-conducting linear media seems complicated, but it's really simple --- if you keep everything straight.
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[@IshaniThakur]

oh thanks for posting it,,,it was very helpful during my final terminal exam :)

[@herbertjamesbanda1084]

You so awesome Sir ... You saved a soul here

[@alaahesham250]

Thank you professor , you are to the point.

[@WalterParsons]

Sweet, man! Just cleared this up way better than my prof

[@jg394]

+Walter Parsons Thanks!

[@ahmadzikwan5674]

really thnks sir its helpful to me in my presentation

[@nabeelidris2734]

Can the total electric and magnetic field in this case be discontinuous across the mirror surface?

[@jg394]

No. They must match exactly at the surface. The only exception is due to the material there will be a field that may add to or subtract from the external field.

[@ghulamhussainkhan7158]

could someone let me know how epsilon 2 v2 = n2. in the last equation.... thanks

[@abhishekpanwar5571]

WHY WE PUT NEGATIVE SIGN TO REFLECTED MAGNETIC FEILD

[@Anna-mt6yh]

I need a topic reflection and transmission at a boundary of non conducting media...plzz

[@drsid23]

Well done -- glad that you caught your error of T for I around 14 minutes. My handwriting looks a lot like yours :>

[@joeljeevantharakan7349]

l0l my handwriting is w0rse than this

[@solarenergytraining750]

How is the perpendicular component of E and B zero?

[@jg394]

The E and B fields in an EM wave are perpendicular to each other and the direction of travel. Since the wave direction is normal to the boundary, the E and B fields must be parallel to it.

[@sankhadeepgain4]

ET = 2 v2/(v1 + v2) you missed the v2 also the n1 in the corresponding equation

[@bitterleinkb9412]

Yes he missed it

[@DS-tg8cj]

What is the relation between B and amplitude of E?

[@hershyfishman2929]

Amplitude of B is 1/v that of E (However, for EM waves in conducting media that's not so, see 8.3.2)

[@ariana5691]

Great video. Question, how could I find the intensities of the incident, reflected and transmitted waves? (I'm given R=0.5, f=500Hz, and pressure amplitude 2Pa)

[@sohaibhassan2750]

u use formula v=rw and w=2*pi*f find v1 and v2 and then find the value of n1 and n2 by using v=c/n and put above the formula u can easily solve this problem otherwise it's my mail I send u [e-mail]

[@rajatligade]

At 3:50 why is there a negative sign for B and not for E? I did not really understand your explanation for that Thank You

[@hershyfishman2929]

Because E_I points in the same direction as E_R (although it travels in the opposite direction which is why κ has a negative sign for E_R). But B_R points in the opposite direction as B_I. Think of it as you walking with your right hand extended where your head points (up) in the direction of E and your right hand in the direction of B. When you hit a wall and turn around and start walking back, your head will continue pointing up, but your right hand will now point in the opposite direction.

[@joeljeevantharakan7349]

ta ta ta tada ta ta ta tada..

[@veronicanoordzee6440]

For you everything is easy and trivial. I don't like your explanations at all!