Kirchhoff's law problems with two circuits

[TJ]

Kirchhoff's Law problem. I have figured most of the problems but these two has me stumped. Please help.


Please see the figures and my questions at http://quasarsvc.bizland.com/DC_Circuit.doc

http://quasarsvc.bizland.com/DC_Circuit.doc

 

[Chen]

Can you show the steps and figures, to find resistor sequence(s) to find Rt so I may work the other values

Find the equivalent resistance of $$R_5$$, $$R_6$$ and $$R_7$$, which are connected in parallel, and call it $$R_{5,6,7}$$. Find the equivalent resistance of $$R_4$$ and $$R_{5,6,7}$$, which are connected in series, and call it $$R_{4,5,6,7}$$. Find the equivalent resistance of $$R_3$$ and $$R_{4,5,6,7}$$, which are connected in parallel, and call it $$R_{3,4,5,6,7}$$. Find the equivalent resistance of $$R_1$$ and $$R_2$$, which are connected in parallel, and call it $$R_{1,2}$$. Finally find the equivalent resistance of $$R_{1,2}$$, $$R_{3,4,5,6,7}$$ and $$R_8$$, which are connected in series, and that is the equivalent resistance of the whole circuit.

 

[Chen]

The numbers in the loop problem represent the potential drop on each of the resistors. To find the value of the potential drops you have to find the current through each of the resistors, and to find that you first need to find the equvilanet reisstance of the whole circuit.

 

[TJ]

1) R567 = 10
2) R567+R4 = 20
3) R4567+R3 = 12
4) R1&R2 = 12
5) R12(12)+R34567(12)+R8(6) = 30 = Rt ?
Appreciate your efforts.
TJ

 

[Chen]

Yes it's $$30\Omega$$ in the first question.

 

[TJ]

Post 237

Thank you for acknowledging the Rt so I can work the rest of them

 

[TJ]

237

Have E1,E2,E3 = 12v
Have I1=0.6, I2=0.4, I3=0.4
Have P1=7.2, P2=4.8,P3=4.8
need understanding of "how to" relating to R4=10, Et=30, Rt=30 It=1.0 to complete E4 or I, and would not that E value be the same for E5, E6, E7, E8?
Thanks
TJ