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# Total resistance question watch

1. Hi all, I'm just wondering am I doing this question on my homework correct so far? I wasn't sure whether or not I should include the internal resistance of the battery when calculating the total resistance of the circuit. I don't include the resistance of the resistor at that point because the circuit leading to the resistor is broken, right? Thanks!

2. (Original post by Marcum)
Hi all, I'm just wondering am I doing this question on my homework correct so far? I wasn't sure whether or not I should include the internal resistance of the battery when calculating the total resistance of the circuit. I don't include the resistance of the resistor at that point because the circuit leading to the resistor is broken, right? Thanks!

You must include the internal resistance.
The 3 resistors (lamps) are in parallel.
This is the external circuit.
The combined resistance for these 3 is in series with the internal resistance of the cell.
3. (Original post by Stonebridge)
You must include the internal resistance.
The 3 resistors (lamps) are in parallel.
This is the external circuit.
The combined resistance for these 3 is in series with the internal resistance of the cell.
Ah, thank you! I got 1.68 Ohms for the total resistance, does that look correct to you?
For the second question I did
V=IR
I =V/R
I = 12/1.68
I = 7.14 A
Is that correct?
4. (Original post by Marcum)
Ah, thank you! I got 1.68 Ohms for the total resistance, does that look correct to you?
For the second question I did
V=IR
I =V/R
I = 12/1.68
I = 7.14 A
Is that correct?
Those are correct.

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