Resistors in Series - summary

1.  The total resistance of resistors in series is their sum.
RTotal = R1 + R2 + …

2.  Current in a circuit is constant from the battery.  If resistors are in series, they all have the same current as the battery delivers.  Calculate this by:
I = V/R

 3.  The resistor voltages in a series circuit add up to the total battery voltage.
Example problem from class:

 R1 = 1 ohm
R2 = 2 ohms
R3 = 3 ohms

 If all 3 resistors are in series with a 12-V battery, the total current is 2-A.  The individual resistor voltages are:  2-V, 4-V, and 6-V.  Note that these add to 12-V.
Try this problem:

 3 resistors (4, 5, and 3 ohms) in series with 36-V.  Find the following:

 - total resistance of the circuit
- current through each resistor
- voltage over each resistor

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