# Circuit Question

Discussion in 'MCAT Study Question Q&A' started by TheRealAngeleno, Aug 14, 2011.

1. ### TheRealAngeleno

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So say I have a circuit with a 12V battery and two resistors Rx and Ry which are in series with one another and say I also have a capacitor which is in parallel with Ry and in series with Rx. Now here's one of the questions to this passage...

Adding a third resistor to the Circuit in such a way that it was in parallel to both Ry and the capacitor would:

A. Increase the current through Rx
B. Decrease the current through Ry
C. Increase the capacitance of C (Capacitor)
D. Decrease the total power drain of the circuit

I selected answer B which is wrong and here's what the answer explanation says. "Parallel pathways are independent of one another so adding a resistor in parallel to Ry results in no change to the current through Ry." But what if we added a Resistor with less resistance in parallel to Ry, wouldn't the current take the path of least resistance and thus more of the current would go through this newly added resistor and so in effect decreasing the current through Ry? Oh, the answer is A btw. Thanks guys!

2. ### costales 2+ Year Member

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The new resistor Ry' in parallel with Ry will create a smaller equivalent resistance, thus increasing the current, which means Ry' || Ry will draw more current through Rx.

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