*Ohm's Law Formulas for D-C Circuits:*

*Ohm's Law Formulas for A-C Circuits:*

In these formulas is the angle of lead or lag between current and voltage and cos = P/EI = power factor.

** Resistors in Series: ** R

*Two Resistors in Parallel:*

*Resistors in Parallel, General Formula:*

*Sinusoidal Voltages and Currents:*

Effective value [Also known as Root-Mean Square (RMS) value] | = | 0.707 x peak value | |

Half Cycle Average value | = | 0.637 x peak value | |

Peak value | = | 1.414 x effective value | |

Effective value | = | 1.11 x average value |

*Resonant Frequency Formulas:*

*Where in the second formula f is in kHz and L and C are in microunits.

*Conductance**: *

*Reactance Formulas**:*

*Impedance Formulas:*

*Q or Figure of Merit:*

*Voltage/Current Phase Rule of Thumb:*

Remember "ELI the ICE man"

ELI: Voltage (E) comes before (leads) current (I) in an inductor (L)

ICE: Current (I) comes before (leads) Voltage (E) in a capacitor (C)