- Ohms Law
- Power Law
- Resistance in Parallel
- Resistance in Series
- Inductance in Parallel
- Inductance in Series
- Capacitance in Series
- Capacitance in Parallel
- Frequency from Wavelength
- Wavelength from Frequency
- Capacitive Reactance
- Inductive Reactance
- Q or Quality Factor
- Unlike Reactances in Series
- Unlike Reactances in Parallel
- Impedance in Series
- Impedance in Parallel
- Resonant Circuit
| Voltage = | Current × Resistance |
| Current = | Voltage ÷ Resistance |
| Resistance = | Voltage ÷ Current |
----------------------------------------------
Power Law
| Power = | Voltage × Current |
| Power = | Voltage2 ÷ Resistance |
| Power = | Current2 × Resistance |
-----------------------------------------------
Resistance in Parallel
RT=1/(1/R1)+(1/R2)+(1/R3)+(1/R.....)
-----------------------------------------------
Resistance in Series
RT=R1+R2+R3+R.....
-----------------------------------------------
Inductance in Parallel
LT=1/(1/L1)+(1/L2)+(1/L3)+(1/L.....)
------------------------------------------------
Inductance in Series
LT=L1+L2+L3+L.....
------------------------------------------------
Capacitance in Series
CT=1/(1/C1)+(1/C2)+(1/C3)+(1/C.....)
------------------------------------------------
Capacitance in Parallel
CT=C1+C2+C3+C.....
------------------------------------------------
Frequency from Wavelength
| 3.00 × 108(m/s) | |
| f(Hz)= | ——————— |
| λ(m) |
where:
| f(Hz)= | the frequency in Hertz |
| m/s= | meters per second |
| λ= | wavelength in meters |
-------------------------------------------------
Wavelength from Frequency
| 3.00 × 108(m/s) | |
| λ(m)= | ——————— |
| f(Hz)(m) |
where:
| f(Hz)= | the frequency in Hertz |
| m/s= | meters per second |
| λ= | wavelength in meters |
----------------------------------------------------
Capacitive Reactance
XC=1/2πfC
where:
| XC= | capacitive reactance |
| π= | 3.14159 |
| f= | frequency in Hertz |
| C= | capacitance in Farads |
----------------------------------------------------
Inductive Reactance
XL=2πfL
where:
| XL= | inductive reactance |
| π= | 3.14159 |
| f= | frequency in Hertz |
| C= | inductance in Henries |
----------------------------------------------------
Q or Quality Factor
| X | |
| Q= | — |
| R |
where:
| Q= | the quality factor |
| X= | the circuit reactance |
| R= | the circuit resistance |
-----------------------------------------------------
Unlike Reactances in Series
jX= XL-XC
where
| jX= | complex circuit reactance |
| XL= | circuit inductive reactance |
| XC= | circuit capacitive reactance |
-----------------------------------------------------
Unlike Reactances in Parallel
| -XL×XC | |
| jX= | ——— |
| XL-XC |
where
| jX= | complex circuit reactance |
| XL= | circuit inductive reactance |
| XC= | circuit capacitive reactance |
Given that this formula is taking into account
all the series and parallel reactances
in the circuit.
------------------------------------------------------
Impedance in Series
Z=√R² + X²
where
| X= | complex circuit reactance |
| R= | total circuit resistance |
| Z= | circuit impedance |
And the resultant phase angle is:
| X | |
| θ= tan-1 | — |
| R |
where
| X= | complex circuit reactance |
| R= | total circuit resistance |
| θ= | current phase angle |
Note:the formulas use the absolute unsigned reactance value.
If the reactance in the circuit is capacitive the phase angle will
be negative. If the circuit reactance is inductive the phase angle
will be positive.
----------------------------------------------------
Impedance in Parallel
| R × X | |
| Z= | ———— |
| √R² + X² |
where
| X= | complex circuit reactance |
| R= | total circuit resistance |
| Z= | circuit impedance |
And the resultant phase angle is:
| R | |
| θ= tan-1 | — |
| X |
Note:the formulas use the absolute unsigned reactance value.
If the reactance in the circuit is capacitive the phase angle will
be negative. If the circuit reactance is inductive the phase angle
will be positive.
-----------------------------------------------------
Resonant Circuit
| 1 | |
| f(Hz)= | ——— |
| 2π√LC |
where
| f(Hz)= | frequency in Hertz |
| L= | inductance in Henries |
| C= | capacitance in farads |
| π= | 3.14159 |
-----------------------------------------------------