Question

A.C. R-L Circuit:
A resistor R is connected in series with an inductor coil having some unknown resistance. The system is subjected to an A.C. supply of peak value V0. The peak voltage dropped across the resistor R and the inductor coil are V1 and V2 respectively. Find:

a) Average power dissipated in the resistor R.
b) Average power dissipated in the resistance of coil.
c) Average power dissipated in the series combination.
d) Resistance of the coil.

Answer 1

I figured a) is V1^2 / 2R

Not sure how to find the rest of the stuff in terms of only V0, V1, V2 and R.

Answer 2

c) will be the sum of a) and b). If the resistance of the coil (d) can be figured out, then b) can be figured out as V2^2 / (2 * coil resistance)

Answer 3

I assume you are getting that by taking rms values?

Answer 4

correct.

Answer 5

Okay. Give me some time to work on it.

Answer 6

Alright. Thanks.

Answer 7

I think.. i think u can model the inductor as a series of a resistor and a superconducting coil..

so the voltage across this whole series is V2 ?

Answer 8

Yes.

Answer 9

I haven't done RL circuits in AC yet so I am finding it quite hard to start.. What I am thinking is that the current through both the resistor and inductor are the same hence we can equate them and try to find out wL. That's just my thought. I am sure Mashy can provide a better solution since he is a Physics teacher.

Answer 10

And the ideal inductor does not dissipate any power. So if we find the resistance of the coil we can find b).