OHM'S LAW: The three forms of Ohm's Law are E = I x R, I = E / R, and R = E / I

WATT'S LAW: The three forms of Watts Law are P = E x I, I = P / E, and E = P / I

Properties

• R_T = Resistance Total; The sum of the individual resistors equals R_T. As resistors are added, R_T increases. As resistors are taken away, R_T decreases.
• I_T = Total Current; Is constant in a series circuit. I_T remains the same at all points in a series circuit.
• E_T = Voltage Total; Each individual resistor in a series circuit will have its own voltage drop across it. The sum of all the voltage drops will equal E_T. ( E_S ) Voltage Source
• P_T = Power Total; Each resistor dissipates power in the form of heat. P_T = E_T x I_T
• The Largest Resistor will have the Largest Voltage Drop( IR ) and the Largest amount of Power being dissipated.

Solving Series Circuits

• To solve series circuits, all you need is Ohm's Law. To find each of the following:
• R_T = R₁ + R₂ + R₃ ......... ect.
• I_T = E_T / R_T
• E_T = I_T x R_T
• You can also find RT by E_T / I_T
• To find each resistors voltage drop: E_R1 = R₁ x I_T, E_R2 = R₂ x I_T, E_R3 = R₃ x I_T, ect.
• To double check your work, each of the individual IR drops should add together to equal E_T

Properties

• Current ( I ) is NOT constant.( Multiple Path's for Current )
• Voltage ( E ) is constant.( Volatge is the same in all Parallel Branches )
• I_T = I₁ + I₂ + I₃ ect. I_T is equal to the sum of the individual current branches.
• R_T = 1 / G_T
• Smallest Resistor will have the Largest I and P
• Add a Resistor = Decrease R_T, Remove a Resistor = Increase R_T
• Resistors of the same value in Parallel Circuits: R_T = Divide one Resistor value by the number of branches.
• R_T in Parallel Circuits will be smaller than the smallest Resistor Value.
• G_T = G₁ + G₂ + G₃ ........ ect.
• P_T = P₁ + P₂ + P₃ ........ ect.

Properties & Solving

• All properties that apply to Series and Parallel Circuits are used.
• Redraw and Reduce entire circuit to a simple series circuit with one Resistor = R_T
• Retrace each step backwards and solve for all parts of the circuit.