Electrical Formulas -1

Electrical Formulas-1

Electrical Current Formulas

1.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)

2.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

3.Electrical Potential or Voltage Formula in DC Circuits

V = I x R

V = P / I

V = √ (P x R)

4.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

5.Electrical Resistance & Impedance Formulas in AC Circuits

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

Z = √(R² + X_L²)… In case of Inductive Load

Z = √(R² + X_C²)…In case of Capacitive Load

Z = √(R² + (X_L- X_C)²---In case of both inductive and capacitive Loads.

Where:

X_L = Inductive reactance= X_L = 2πfL…Where L = Inductance in Henry

And

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

Electrical Power Formulas

6.Electrical Power formulas in DC Circuits

P = VxI

P = I²R

P = V²/R

7.Electrical Power formulas in Single Phase AC Circuits

P = VxI Cosθ

P = I² x R Cosθ

P = (V²/R) Cosθ

8.Electrical Power formulas in Three Phase AC Circuits

P =√3 x V_LxI_L Cosθ

P =3 x V_PxI_P Cosθ

P =3 I² x R Cosθ

P =3 (V²/R) x R Cosθ