Electricity & Magnetism Calculators — Ohm's Law & Circuits
Solve Ohm's law (V = IR), Coulomb's law, and series/parallel circuit problems. Calculate current, resistance, capacitance, electric fields, and magnetic forces.
Electricity & Magnetism Calculators
Capacitance Calculator
Calculate capacitance for parallel plate capacitors, series and parallel combinations. Find stored charge, energy, and electric field strength instantly.
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Coulomb\u2019s Law Calculator
Calculate electrostatic force between two charges using F = kQ\u2081Q\u2082/r\u00B2. Find attraction or repulsion from charges, distance, and sign of each charge.
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Current Calculator
Calculate electric current using Ohm\u2019s Law I = V/R. Enter voltage and resistance to find current in amps, plus power dissipation and circuit analysis.
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Electric Field Calculator
Calculate electric field strength from point charges using E = kQ/r\u00B2. Find field direction, magnitude, and superposition of multiple charges.
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Electric Potential Calculator
Calculate electric potential using V = kQ/r. Find voltage at a point due to point charges, superposition of multiple charges, and potential difference.
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Magnetic Force Calculator
Calculate magnetic force on a moving charge (F = qvBsinθ) or current-carrying wire (F = BILsinθ). Find force, radius of circular motion, and deflection.
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Ohm\u2019s Law Calculator
Solve Ohm\u2019s Law V = IR for any variable. Enter two of voltage, current, and resistance to find the third instantly, plus power and energy calculations.
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RC Circuit Time Constant Calculator
Calculate the RC time constant τ = RC. Find charging and discharging voltage, current at any time, half-life, and percent charged for any RC circuit.
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Resistance Calculator
Calculate total resistance for series and parallel circuits. Add up to 10 resistors and find equivalent resistance with step-by-step solutions.
Use CalculatorUnderstanding Electricity & Magnetism
Electricity and magnetism are two aspects of a single fundamental force — electromagnetism. Electric charges produce electric fields, and moving charges (currents) produce magnetic fields. Ohm's law (V = IR) governs the simplest circuits: a 9 V battery connected to a 3 Ω resistor drives a 3 A current and dissipates 27 W of power. These basic relationships scale up to analyze complex circuits with series and parallel combinations, capacitors, and inductors.
Coulomb's law describes the force between stationary charges with the same inverse-square form as gravity: F = kq<sub>1</sub>q<sub>2</sub>/r². Electric fields map these forces across space, and when charges move through fields they gain kinetic energy — the direct link between electromagnetism and energy, work & power. A single electron accelerated through 1 V gains 1.6 × 10¹&sup8; J of kinetic energy (one electron-volt).
Magnetic forces act on moving charges and current-carrying wires, governed by F = qvB sin(θ). This connection between electricity and magnetism underpins motors, generators, and electromagnetic waves. Our optics & light calculators explore what happens when oscillating electric and magnetic fields propagate through space as light.