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