# Homework Help: Yet another question on circuits!

1. Nov 2, 2005

### QueenFisher

i've been given this circuit, i know the e.m.f. and internal resistance, it has 2 resistors connected in parallel so i can work out Rtotal, but i need to work out the current through one of the resistors. can anyone point me in the right direction?
thanks

2. Nov 2, 2005

### verty

Well, once you know R you can calculate the total current. With the current, you can calculate the volt-drops certain resistances, etc. That's generally the approach to take.

3. Nov 2, 2005

### QueenFisher

so do i take the e.m.f. as being the supply voltage in this case? cos i can't think of any other way to find it

4. Nov 2, 2005

### ranger

The internal resistance [of the battery] acts as if it were a resistor in series with the battery. You could find the ternimal voltage.
$$V_{ab} = \varepsilon - Ir$$

$$\varepsilon$$ = Emf
$$r$$ = internal resistance

USing ohms law we get.
$$IR = \varepsilon -Ir$$

Where $$R$$ is the 2 resistors in parallel.

I'm sure you can take it from here.

Last edited: Nov 2, 2005