Current Divider Confusion

[JacobEdward]

https://youtu.be/hjq1Kf9hiGY

I am measuring 4.83 mA across R3 and this is the table I used to calculate what values I should have been receiving... can someone check my math or maybe come up with some ideas of why I'm getting 4 mA less than I should be?

______________R1________R2________R3_______Total
Voltage_______12.7_______12.7______12.7_______12.7
Current______0.000235__0.000642___0.000863___0.00174
Resistance____54000_____19760_____14700___7291.126531

I'm following this basic circuit configuration:

http://www.allaboutcircuits.com/vol_1/chpt_6/3.html

[AlfBaz]

Assuming you've connected your ammeter in series then most likely you are seeing the effect of burden voltage

[JacobEdward]

Assuming you've connected your ammeter in series then most likely you are seeing the effect of burden voltage

Yes, the ammeter is in series, thanks, forgot to mention that in the description

[IanB]

Note that 0.000863 A is 0.863 mA. Given that you appeared to measure 4.83 mA, something is far more wrong than you state in your post.

You really need two meters here so that you can measure both voltage and current at the same time without swapping leads around and twisting the range selector.

You should test a single resistor. Measure the voltage and current at the same time and calculate the resistance. (Make sure to measure the voltage across just the resistor so the ammeter doesn't interfere with the reading.) Then take the resistance out of circuit and measure the resistance using the resistance range on a meter. Check that they match.

After that, try to repeat your experiment, taking great care over every detail.

Also, be careful with that big ass lead acid battery. One false move and you will let the magic smoke out of everything in the vicinity, start a fire and burn yourself all in one go.