# Homework Help: Current Electricity

1. Oct 23, 2009

### kevindesai777

1. The problem statement, all variables and given/known data
Three resistances of 4,6,12 ohms are connected in parallel and the combination is connected in series with a 4V battery with internal resistance 2 ohms The battery current is what

2. Relevant equations
No relevant question.

[b]3. The attempt at a solution[/b]
I dont know

2. Oct 23, 2009

### willem2

replace parallel or series combinations of resistances by their equivalent until you have only 1 resistance left.

3. Oct 23, 2009

### dreamspace

I = $$\frac{E}{R}$$ = $$\frac{4V}{Ri+(R1||R2||R3)}$$ = $$\frac{4V}{2 ohm + (\frac{1}{4 ohm}+\frac{1}{6 ohm}+\frac{1}{12 ohm})}$$ = $$\frac{4V}{2 ohm}$$ = 2A

4. Oct 23, 2009

### willem2

What happened to this? $$(\frac{1}{4 ohm}+\frac{1}{6 ohm}+\frac{1}{12 ohm})$$

5. Oct 27, 2009

### kevindesai777

thank u

6. Oct 27, 2009

### willem2

I didn't notice it the first time but (R1||R2||R3) =

$$1 / (\frac{1}{4 ohm}+\frac{1}{6 ohm}+\frac{1}{12 ohm})$$