Initially a single resistor R1 is connected to a battery. Then another resistor
ID: 1950283 • Letter: I
Question
Initially a single resistor R1 is connected to a battery. Then another resistor R2 (different from R1) is added in parallel. Which one of the following is ALWAYS TRUE?A) The current through R1 now is the same as that before R2 is added.
B) The current through R1 now is less than that before R2 is added.
C) The current through R1 now is more than that before R2 is added.
D) The total current through R1 and R2 is the same as that through R1 before R2 is added.
E) The total current through R1 and R2 is twice as that through R1 before R2 is added.
Why is the answer A? If they were connected in series, then I would understand, but the fact that they're connected in parallel means that the current splits, and hence should be smaller after the introduction of R2.
Explanation / Answer
No, your reasoning is okay but it's not actually true. Since R1 and R2 are purely in parallel, you have the same voltage across each element -- the voltage of the source. By connecting R2 in parallel you're DRAWING more current from the source by lowering the overall resistance, but you're not LOWERING the current at all from each resistor-- you're getting more!