Basic ConceptsCircuit AnalysisElectrical DesignElectrical FundamentalsFormulas - Equations

Formula & Equations for Ohm’s, Kirchhoff’s & Coulomb’s Laws

Ohm’s Law, Kirchhoff’s Laws (KVL & KCL ) & Coulombs Laws Formulas & Equations

Formula & Equations for Ohm's, Kirchhoff's & Coulomb's Laws

Ohm’s Law Formulas

Ohm’s law shows the relationship between current “I” & the voltage “V” where the resistance “R” is a constant in an electrical circuit.

Ohm’s Law in DC Circuits

  • I = V/R            For current calculation
  • V = IR             For voltage calculation
  • R = V/I            For resistance calculation

Ohm’s Law in AC Circuits

  • I = V/Z             For current calculation
  • V = IZ              For voltage calculation
  • Z = V/I             For impedance calculation

Where

  • I = Current in Amperes (A)
  • V = Voltage in Volts (V)
  • R = Resistance in Ohms (Ω)
  • Z = Impedance in Ohms (Ω)

Kirchhoff’s Current Law – KCL

Summation of all currents entering a node or junction is 0. Or the sum of entering and leaving currents  at a point is zero. In other words, the current entering at a point is equal to the current leaving that point.

Kirchhoff’s Current Law

∑IEntering = ∑ILeaving

∑I = 0

  • Current entering the node is denoted with positive sign (+).
  • Current leaving the node is written with a negative sign (-).

Kirchhoff’s Voltage Law – KVL

Summation of all potential differences in a circuit loop is 0. The product of I “Current” and R “Resistance” in a closed path (also known as mesh) located in a network is equal to the applied EMF.

Kirchhoff’s Voltage Law

IR = ∑E

Coulomb’s Law

Coulomb’s laws of electrostatics provides the force of attraction or repulsion between two charges or charged bodies.

Coulomb’s Law

or
Coulomb’s constant

  • F = force of repulsion or attraction between charges
  • ε0 = permittivity in space
  • εr = relative permittivity of material
  • q1, q2 = 1st & 2nd amount of charge respectively in coulombs
  • r = Distance between the charges in meters
  • k = constant

Related Formulas and Equations Posts:

Electrical Technology

All about Electrical and Electronic Engineering & Technology. Join us on WhatsApp at Electrical Technology Official Channel, to receive the latest content, articles, and updates. You can also like and follow our social media networks below, or subscribe with your email to receive premium engineering articles in your mailbox.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button