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Circuit question

hey, so I'm stuck on part b.

I know for part a) the voltage is: (0.24A)(15) = 3.6V

and for part b) I did 6 / 4 = 1.5 A but this is wrong??

circuit.JPG35.5KB

Reply 1

atsruser

Original post by Ravster

hey, so I'm stuck on part b.

I know for part a) the voltage is: (0.24A)(15) = 3.6V

and for part b) I did 6 / 4 = 1.5 A but this is wrong??

Note that since the 4 ohm and parallel pair are in series, then:

6 = V_{4 \Omega} + V_{\parallel}

and you already know

V_{\parallel}

Reply 2

wew.lad

Try to do a Kirchhoff's second law loop. Something useful for me when dealing with electricity questions was learning the correct definition of Kirchhoff's second law, where the some of all p.ds in any loop = 0.

There's three (or four if you could consider the parallel component as one part) potential loops for this circuit. The equation for one going through the 4 ohm resistor and resistor R would be:

6 - 4I1 - RI2 = 0

Basically, find the single loop or path in the circuit that leaves I1 as the only remaining variable.