# Calculate the current being drawn from a battery

1. Jan 1, 2004

### qim

If I have a question asking to calculate the current being drawn from a battery can I, or rather should I, give an answer in Ohms?

I hate electricity...

Thanks and a Happy New Year to you all.

qim

2. Jan 1, 2004

### Jimmy

Resistance is measured in ohms. Current is measured in amps.

3. Jan 1, 2004

### qim

Hi Jim

Thanks, the penny is dropping...

I have been given the voltage and the resistances

So I guess I can work out the total resistance and then use P = V^2/R

and from there P = V/I > I = V/P

Just thinking aloud but I would be grateful if you could confirm that I am on the right track.

Thanks

qim

4. Jan 1, 2004

### Mathechyst

Wouldn't it be easier to use Ohm's Law?

Doug

5. Jan 1, 2004

### qim

Thanks Doug

"What's that?", you probably heard me say...

Yes, I got it, thanks very much.

qim

6. Jan 2, 2004

### Jimmy

Actually, E is more commonly used to symbolize voltage. The unit of measure for voltage(E) is the Volt(V). E = 10V for example. Anyway,

$$P = E I$$

So to calculate the current with a given Voltage and Power:

$$I = \frac{P}{E}$$

You could save yourself a step and use

$$I = \frac{E}{R}$$

Last edited: Jan 2, 2004