Electrolyte Madness

[deleted-42063]

I'm doing this project for my school fair I'm nearly done with it but i still don't know why we use the 9 volt battery if the current is going to come from the orange juice? i don't know th answer to that question
plzzzz help
Due in a week

[deleted-71588]

why we use the 9 volt battery if the current is going to come from the orange juice

You need to go back and CAREFULLY re-read the project idea. Somewhere in the project idea it mentions that you are going to measure "conductance". Have you done any reasearch on "conductance"? Look it up a good dictionary because I suspect you are confused.

Conductance is a property of materials that quantifies how easily they allow electrons to flow through them.

If you have read some of the other project ideas that involve making a battery out of dissimilar metal electrodes in an electrolyte solution and are confusing what happens with the orange juice and/or sport drink being an electrolyte in this experiment, you missed the difference. In this experiment, you are using the SAME metal for both electrodes. This means the electrodes and electrolyte will NOT function as a battery and produce current.

The battery in this circuit is the voltage/current source. The ampmeter measures the current and represents a constant load. The electrodes and electrolyte is the only variable in the circuit and you are measuring the conductance (or if you take the reciprical or look at the ratio upside down or in the opposite way, the resistance).

V (voltage) = I (current) * R (resistance) or V = I (current) / G (conductance). R (resistance) = 1 (constant one) / G (conductance).

The "current" does NOT "come from the orange juice" in the sense that it originates from the orange juice.
The current flows through the orange juice.

You can prove this to yourself by altering the circuit. Hook the ampmeter directly to the two electrodes in the orange juice (with out any battery involved). You should see NO current indication.

CAUTION: You SHOULD NOT attempt to hook the battery to both leads of the ampmeter to prove it is the source of power as there isn't anything to limit the current flow so you would likely bend the indicator needle of an analog ampmeter and possibly blow an internal fuse on a digital ampmeter, or if the ampmeter was capable of measuring the maximum current the battery can produce, the battery could get VERY HOT and some high current varieties might even burst or have an internal cell to cell connection destroyed.