- #1
Flucky
- 95
- 1
Homework Statement
Use Kirchhoff’s junction rule and loop rule (twice) to find the effective resistance of the two
resistors connected in parallel as shown, and demonstrate that this agrees with the expression 1/R = 1/R1 + 1/R2
(poorly drawn picture of the circuit)
The Attempt at a Solution
Using Kirchoff's 1st law:
I1 = I2 + I3
Using Kirchoff's 2nd law:
E - I2R1 = 0 ... [1]
and
I2R1 - I3R2 = 0 ... [2]
Now I think I can say that E = I1R
Subtituting that into equation [1] gives:
I1R - I2R1 = 0
Now here's where I'm having difficulty, I keep trying out different ways of substituting the equations into one another but end up with stupid answers like R = R2...
Could anyone point me in the right direction?
Thanks in advance