(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two batteries and three resistors are connected as shown in the figure. How much current flows through the 9.0 V battery?

(a) When the switch is closed?

(b) When the switch is open?

2. Relevant equations

Kirchhoff's Loop Rule

I=V/R

3. The attempt at a solution

To find the current when the circuit is open, I totally disregarded the 5 ohm resistor and found the equivalent resistors of 2 and 4 and got 6. Then I used the equation I=9V/6 and that didn't work.

For the current when the circuit is closed, I applied Kirchhoff's Loop rule and found the current for each loop then solved by adding the two. That didn't work so I redrew the diagram and placed the 5 ohm resistor between the 2 and 4 ohm resistor and tried to figure out the current of that loop, but it also didn't work.

Additionally, does the 6 V battery in the drawing have anything to do with achieving the correct answer?

Thank you very much.

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# Closed/Open DC Circuits

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