**Electrical Formulas**

**Electrical Current Formulas**

**Electrical Current Formulas in DC Circuit**

I=V/R

I = P/V

I = √P/R

*Where

*I = Current in Amperes (A)*

*V = Voltage in Volts (V)*

*P = Power in Watts (W)*

*R = Resistance in Ohm (Ω)*

**Electrical Current Formulas in Single Phase AC Circuit**

I = P / (V x Cosθ)

I=(V/Z) …Where Z = impedance = Resistance of AC Circuits

Electrical Current Formulas in Three Phase AC Circuit

I = P / √3xVxCosθ

**Voltage or Electrical Potential Formulas**

**Electrical Potential or Voltage Formula in DC Circuits**

V = I x R

V = P / I

V = √ (P x R)

**Voltage or Electrical Potential Formulas in Single Phase AC Circuits**

V = P/(IxCosθ)

V = I / Z… Where Z = impedance = Resistance of AC Circuits

**Electrical Resistance Formulas**

R = V/I

R = P/I

^{2}R = V

^{2}/P**Electrical Resistance & Impedance Formulas in AC Circuits**

In AC Circuits (Capacitive or inductive Load), Resistance = Impedance i.e., R = Z

Z = √(R

^{2}+ X_{L}^{2})… In case of Inductive LoadZ = √(R

^{2}+ X_{C}^{2})…In case of Capacitive LoadZ = √(R

^{2}+ (X_{L}– X_{C})^{2}…In case of both inductive and capacitive Loads.***Good to know:**

Where;

X

_{L }= Inductive reactance= X

_{L }= 2πfL…Where L = Inductance in HenryAnd;

Xc = Capacitive reactance

= Xc = 1/2πfC… Where C = Capacitance in Farads.

**Electrical Power Formulas**

**Electrical Power formulas in DC Circuits**

P = VxI

P = I

^{2}RP = V

^{2}/R**Electrical Power formulas in Single Phase AC Circuits**

P = VxI Cosθ

P = I

^{2}x R CosθP = (V

^{2}/R) Cosθ**Electrical Power formulas in Three Phase AC Circuits**

P =√3 x V

_{L}xI_{L}CosθP =3 x V

_{P}xI_{P}CosθP =3 I

^{2}x R CosθP =3 (V

^{2}/R) x R Cosθ