Recent content by randybryan

  1. R

    Induction in two coils that are connected :S

    Haha, finally. Thanks. So is the potential difference between the crossing points emf1 - emf 2?
  2. R

    Optics question - Don't know if anyone can help

    Of course! I put the line in every other place but there. Thanks for the help
  3. R

    Induction in two coils that are connected :S

    ok yeah sorry so I(t)(R1 + R2) = -π(r12+r22)ωB0cosωt but it still holds that I(t)= (EMF1 + EMF2)/(R1 + R2) right?
  4. R

    Induction in two coils that are connected :S

    Ok, so using Faraday's law and Ohm's law and assuming current density J is constant throughout at time t, I got EMF (total) = I(t)(R1 + R2)=-ωB0cosωt and if EMF1 + EMF2 = EMF(Total) I(t) = (E1 + E2)/(R1 + R2) Is that right or am I just making the same mistakes?
  5. R

    Optics question - Don't know if anyone can help

    I've attached a screenshot of the question, and I have to admit I'm really struggling. I don't know if anyone will be able to help as optics is very diagram-dependent, but perhaps you can give me a hint without needing to draw anything. I'm stuck on (ii) a) The first thing I did was use...
  6. R

    Induction in two coils that are connected :S

    That the sum of the voltages should be equal to zero? Sorry, I realize I'm being stupid, I just really don't know where I'm going with this. Wouldn't that imply EMF1=-EMF2?
  7. R

    Induction in two coils that are connected :S

    I think Faraday's law has B in it? I'm sure that was just a typo. I'm not sure how to integrate E though as it's not a static E field?
  8. R

    Induction in two coils that are connected :S

    Ah of course! So the total emf is equivalent to that of a single loop with radius r1 + r2? Still struggling to bring in resistance.
  9. R

    Induction in two coils that are connected :S

    EMF1 = -π(r1)2B1ω1cos(ω1t) EMF2 = -π(r2)2B2ω2cos(ω2t) if ω1=ω2 EMFTotal = -πωcos(ωt){B1(r1)2 + B2(r2)2) Is this the right approach?
  10. R

    Induction in two coils that are connected :S

    Hmmm ok, but then if I can't use EMF = i×R how can I write the equation in terms of R?
  11. R

    Induction in two coils that are connected :S

    Thanks. Does that mean I equate E(total) with the E I got for the single loop?
  12. R

    Induction in two coils that are connected :S

    V = V1 + V2? So E1 + E2 = Etotal ?
  13. R

    Induction in two coils that are connected :S

    using Faraday's law, but this is where I got stuck. Do I treat each loop separately? Do I work out the EMF in loop 1 and then loop 2? I'm guessing there is self interaction going on here (well that's what induction is), but I don't know how to set up the equation. If I take the larger loop I can...
  14. R

    Induction in two coils that are connected :S

    So is EMF = i(R1 + R2)? Or am I still missing the point?
  15. R

    Induction in two coils that are connected :S

    Presumably you could represent as a series circuit with two separate resistances so their resistances add? R1 + R2?
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