I thought I finally had a grasp on how ohm's law works but when I set up an actual experiment, the numbers don't match up. To keep a long story short, I converted a computer power supply into a lab power supply and I need a dummy load of some kind. I decided to try to build one. My first attempt was a nichrome coil at roughly 12ohms inside of a pvc pipe which I filled with plaster. It became dangerously hot after just a few minutes so back to the drawing board. As a temporary solution I decided to try electrolysis in an electrolyte solution of baking soda and water. This is where I must be calculating or doing something wrong. To test this load I used a laptop charger (19v). Using a multimeter I checked the resistance of the solution through the carbon rods I had suspended in the solution and got a reading of 4500 ohms (4.5 on 20k setting). When I wired the multimeter into the circuit to test amperage it showed roughly 3.3 amps... If V=I*R, the 19 volts divided 4500 ohms should only be .004 amps. How did I get 3.3 amps?? As I'm writing this question, I'm starting to think the laptop charger works on constant current, is that why? Or am I using ohms calculations wrong? Or what else is happening here?
Image 2 is the ohm reading. It shows 4.84 on the 2000k setting.