Need some electrical engineering assistance

[JPG]

Just be aware that if you change the voltage the current will change, if you change the solution the current changes, if you change the electrodes the current changes.

Why do dat seem familiar?:D

[dusty]

Why do dat seem familiar?:D

Beats me! Why?

[JPG]

Beats me! Why?

Maybe post 2 this thread!:D

[heathicus]

So when you say "current", do you mean "amperage"?

In terms of volts and amps, what is "current"?

And my personal hypothesis is that various voltages all at the same amps will result in no difference. My son's hypothesis is that it will. I haven't told him my hypothesis.

[JPG]

So when you say "current", do you mean "amperage"?

In terms of volts and amps, what is "current"?

And my personal hypothesis is that various voltages all at the same amps will result in no difference. My son's hypothesis is that it will. I haven't told him my hypothesis.

'Current' is measured in amperes.

'Electromotive force' is measured in volts.

Resistance is measured in ohms.

Power is measured in watts.

Thus I = E/R means Amperes = Volts/Ohms

And P = IE means Watts = Amperes x Volts

Question is, what 'hypothesis' did he turn in. That will alter the test conditions and explain your emphasis on voltage variance.

Truth be told, this experiment would be a good 'example' of disproving an incorrect hypothesis. He needs to understand that when writing his 'report'.

[BuckeyeDennis]

So when you say "current", do you mean "amperage"?

In terms of volts and amps, what is "current"?

And my personal hypothesis is that various voltages all at the same amps will result in no difference. My son's hypothesis is that it will. I haven't told him my hypothesis.

Yes, current and amperage are synonyms, electrically speaking. The unit of measure of current is the Ampere (named after an early scientist in the field), and abbrievated "Amp", or simply "A". Volts, by the way, are named in honor of Volta, a physicist.

A simple yet useful analogy for electrical circuits is fluid flow. Think of water in a pipe. The higher the pressure, the faster the water wants to flow. Electrical current is analogous to water flow rate. Any restriction in a water line tends to generate back pressure, and thus reduce the flow rate. This flow restriction is analogous to electrical resistance. And voltage is analogous to water pressure. In fact, Ohm's law states that the current between two points in a circuit is proportional to the voltage across those two points. Yup, you guessed it, the unit of measure of electrical resistance is the Ohm, so named after German physicist George Ohm.

Now given a particular flow restriction, you cannot control both the flow rate and the pressure. If you apply a given pressure, a certain flow rate will result. Conversely, if you pump water through the restriction at a given rate, a certain pressure drop will result.

In the electrical problem at hand, we are all advising you to adjust the electrical resistance of the electrolysis tank, by any of the means that JPG enumerated, so that an acceptable current results when you apply a fixed voltage from one of your available voltage supplies.

[JPG]

Just like a Dust Collection system!:D Pressure, Static pressure change, Volume.

I believe we are looking at this from the wrong angle. We be attempting to 'demonstrate' the effect of different currents.

The kid's hypothesis is that voltage will do that. He needs to set it up to attempt to prove his hypothesis by holding all three sample currents the same, but vary the applied voltage. That means he adjusts the spacing to create all three currents the same with different applied voltages.

He shall only prove the invalidity of his hypothesis.(Assuming we know of that which we 'speak':D)

No joy, but good science.




I hope his science teacher has good head alignment!:rolleyes:

[heathicus]

So if I add a resistor as suggested, that actually increases current /amps? Like holding your thumb over the end of a water hose to make it spray harder?

[BuckeyeDennis]

So if I add a resistor as suggested, that actually increases current /amps? Like holding your thumb over the end of a water hose to make it spray harder?

No, adding a resistor increases the "restriction", which reduces the current flow. But I earlier recommended using a low resistance that will have no significant impact on the experiment.

In your water hose scenario, your thumb forms a flow restriction, which decreases the water flow rate (in gallons per minute). What you are observing is an increase in water velocity -- a related but different thing. Flow rate can easily be determined by seeing how long it takes to fill a gallon bucket with water. If you partially block the hose with your thumb, it WILL take longer to fill the bucket.

[heathicus]

Thanks for the clarification. Posts 8-10 had me confused on that matter, but reading your clarification and re-reading those posts, I think I'm getting it. But, every time I think I've got it, I don't!

So, for the sake of education, say I'm using a battery charger with a car battery for electrolysis. The battery should be connected parallel - both leads from the charger to the battery, then both leads from the battery to the electrolysis setup (positive to the anode/sacrificial metal, negative to the cathode/part to be cleaned). To check the voltage with my multimeter, I would connect the leads across in parallel as well. To check the current (as measured in amps), I would have to break the circuit from battery to the cathode and connect the multimeter in series. Correct?