1. 220  470  Gnd5V Currents Through Parallel Resistors 1 living with the lab © 2012 David Hall

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3. Select Resistors Find the 220  and the 470  resistors from your parts kit. Now, find the 220  resistor. Example: 470  resistor 4 = yellow 7 = violet Add 1 zero to 47 to make 470, so 1 = brown So, 470 = yellow, violet, brown colordigit black0 brown1 red2 orange3 yellow4 green5 blue6 violet7 gray8 white9 first digit second digit number of zeros tolerance gold = ±5% silver = ±20% 3 living with the lab

4. build the parallel circuit below measure the total current from the power source Compute the current after you make your measurement. current flow 4 living with the lab use Ohm’s law: compare

5. Compute the current after you make your measurement. current flow 5 living with the lab modify the parallel circuit as show measure the total current through the 220Ω resistor use Ohm’s law: compare

6. Compute the current after you make your measurement. 6 living with the lab modify the parallel circuit as show measure the current through the 470Ω resistor compare use Ohm’s law:

7. ~ ~ I = 22.7 mA I = 10.7 mA more current goes through smaller resistor I = 33 mA 7 living with the lab check for conservation of charge Kirchoff’s Current Law (KCL) The algebraic sum of currents entering a node is zero. Current In = Current Out