EEE Electrical Formulas

EEE Formulas is a clear reference of electrical and electronics formulas for students, technicians and hobbyists: 144 highlighted formulas in 61 topics, from Ohm's law and DC circuits to AC power, three-phase systems, transformers, semiconductors, op-amps and digital logic.
Every formula is typeset cleanly, every symbol is explained with its SI unit, and 68 original circuit diagrams and graphs show what the formula means. It all works offline.

Each topic gives the key electrical engineering formulas, says when to use them and works through examples with real numbers. Practice questions with tap-to-reveal answers help you check what you have learned.

What you will learn

• Basic Quantities and Units: SI units and prefixes, charge and current, voltage and EMF, Ohm's law, electric power, energy, kWh and efficiency, resistivity and wire resistance, Coulomb's law and electric field
• DC Circuits: resistors in series and parallel, voltage and current dividers, Kirchhoff's laws, mesh analysis, nodal analysis, star–delta resistor conversion, the Wheatstone bridge
• Network Theorems: Thevenin's theorem, Norton's theorem and source conversion, superposition, maximum power transfer
• Capacitors and Inductors: capacitance, inductance, series and parallel combinations, RC charging and discharging, RL circuits and the time constant
• AC Circuits: peak, RMS and average values, phase and phasors, reactance, impedance and admittance, series and parallel RLC circuits, resonance, Q factor and bandwidth, AC power and power factor, power factor correction
• Three-Phase Systems: three-phase basics, star and delta connections, three-phase power
• Transformers and Machines: the ideal transformer, transformer losses and efficiency, DC motors and generators, AC motor speed and slip
• Semiconductors: diodes, rectifiers and smoothing, the Zener diode regulator, the LED series resistor, bipolar junction transistors, MOSFETs
• Op-Amps, Filters and Decibels: op-amp basics, inverting and non-inverting amplifiers, summing and difference amplifiers, integrator and differentiator, RC low-pass and high-pass filters, dB, dBm, dBW and dBV
• Digital Electronics: number systems, logic gates and truth tables, Boolean algebra and De Morgan's laws
• Components, Codes and Safety: circuit symbols, the resistor colour code, standard E-series values, electrical safety and mains voltage

Features
• 144 highlighted electrical and electronics formulas in 61 topics and 11 sections
• Every symbol listed with its meaning and unit
• 83 worked examples with the steps shown
• 160 practice questions with tap-to-reveal answers
• 68 original diagrams: schematics, phasor diagrams, power triangles, RC charging curves, resonance curves and filter responses
• 30 reference tables
• Search all topics from the home screen
• Previous and Next buttons to work through a section in order
• Dark mode that follows your phone's setting
• Works offline, no account needed
• Available in 8 languages: English, Español, Português, Français, Deutsch, العربية, हिन्दी and Bahasa Indonesia

Who it is for
• Electrical and electronic engineering (EEE) students in diploma, polytechnic and first university courses
• Electricians, technicians and apprentices who need Ohm's law, power factor or three-phase formulas at hand
• Electronics hobbyists working out an LED resistor, a voltage divider or an op-amp gain
• Teachers and tutors who want a reliable electrical formulas sheet

EEE Formulas is an independent study aid. Content is checked against OpenStax University Physics Volumes 2 and 3, NIST CODATA 2022, IEC and IEEE standards and standard textbooks. It is not affiliated with any exam board, textbook publisher or standards body. Always follow local wiring regulations, and work on mains equipment only if you are qualified.

Recent changes:
Improved Arabic display: maths, codes and English names in tables now read in the right order.