Physics Formulae/Electric Circuits Formulae
Lead Article: Tables of Physics Formulae
This article is a summary of the laws, principles, defining quantities, and useful formulae in the analysis of Electric Circuits, Electronics.
DC Quantities
editQuantity (Common Name/s) | (Common) Symbol/s | Defining Equation | SI Units | Dimension |
---|---|---|---|---|
Electrical Resistance | Ω = V A-1 = J s C-2 | [M][L]2 [T]-3 [I]-2 | ||
Resistivity, Scalar | Ω m | [M]2 [L]2 [T]-3 [I]-2 | ||
Resistivity Temperature Coefficient,
Linear Temperature Dependance |
K-1 | [Θ]-1 | ||
Terminal Voltage for
Power Supply |
V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
Load Voltage for Circuit | V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
Internal Resistance of
Power Supply |
Ω = V A-1 = J s C-2 | [M][L]2 [T]-3 [I]-2 | ||
Load Resistance of
Circuit |
Ω = V A-1 = J s C-2 | [M][L]2 [T]-3 [I]-2 | ||
Electromotive Force (emf), Voltage across
entire circuit including power supply, external components and conductors |
V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
Electrical Conductance | S = Ω-1 | [T]3 [I]2 [M]-1 [L]-2 | ||
Electrical Conductivity, Scalar | Ω-1 m-1 | [I]2 [T]3 [M]-2 [L]-2 | ||
Electrical Conductivity, Tensor | Ω-1 m-1 | [I]2 [T]3 [M]-2 [L]-2 | ||
Electrical Power | W = J s-1 | [M] [L]2 [T]-3 | ||
emf Power | W = J s-1 | [M] [L]2 [T]-3 | ||
Resistor Power Dissipation | W = J s-1 | [M] [L]2 [T]-3 |
Resistors in Series | |
Resistors in Parallel |
Ohm's Law | Scalar form
Vector Form
Tensor Form, general applies to all points in a conductor
|
Kirchoff's Laws | emf loop rule around any closed circuit
Current law at junctions
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AC Quantitites
editQuantity (Common Name/s) | Common Name/s | Quantity (Common Name/s) | Quantity (Common Name/s) | Quantity (Common Name/s) |
---|---|---|---|---|
Resistive Load Voltage | V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
Capacitive Load Voltage | V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
Inductive Load Voltage | V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
Capacitive Reactance | Ω-1 m-1 | [I]2 [T]3 [M]-2 [L]-2 | ||
Inductive Reactance | Ω-1 m-1 | [I]2 [T]3 [M]-2 [L]-2 | ||
AC Impedance |
|
Ω-1 m-1 | [I]2 [T]3 [M]-2 [L]-2 | |
Phase Constant | dimensionless | dimensionless | ||
AC Circuit Resonant
Pulsatance |
s-1 | [T]-1 | ||
AC Peak Current | A | [I] | ||
AC Root Mean
Square Current |
A | [I] | ||
AC Peak Voltage | V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
AC Root Mean
Square Voltage |
V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
AC emf, Root Mean Square | V = J C-1 | [M] [L]2 [T]-3 [I]-1 | ||
AC Average Power | W = J s-1 | [M] [L]2 [T]-3 | ||
Capacitive Time Constant | s | [T] | ||
Inductive Time Constant | s | [T] |
RC Circuits | RC Circuit Equation
RC Circuit Capacitor Charging
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RL Circuits | RL Circuit Equation
RL Circuit Current Rise
RL Circuit, Current Fall
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LC Circuit | LC Circuit Equation
LC Circuit Resonance
LC Circuit Charge
LC Circuit Current
LC Circuit electrical potential energy
LC circuit magnetic potential energy
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RLC Circuits | RLC Circuit Equation
RLC Circuit Charge
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