General Uses Electrical Formulas

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/I2

R = V2/P

Electrical Resistance & Impedance Formulas in AC Circuits

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

Z = √(R2 + XL2)… In case of Inductive Load

Z = √(R2 + XC2)…In case of Capacitive Load

Z = √(R2 + (XL- XC)2…In case of both inductive and capacitive Loads.

*Good to know:

Where;

XL = Inductive reactance

= XL = 2πfL…Where L = Inductance in Henry

And;

Xc = Capacitive reactance

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

Electrical Power Formulas

Electrical Power formulas in DC Circuits

P = VxI

P = I2R

P = V2/R

Electrical Power formulas in Single Phase AC Circuits

P = VxI Cosθ

P = I2 x R Cosθ

P = (V2/R) Cosθ

Electrical Power formulas in Three Phase AC Circuits

P =√3 x VLxIL Cosθ

P =3 x VPxIP Cosθ

P =3 I2 x R Cosθ

P =3 (V2/R) x R Cosθ