App Description

Solving Ohms law for DC (E=I*R) is straight forward but what about AC. For AC (E=I*Z) looks simple but the value Z is composed of an inductor (a coil of wire) and a Capacitor. The AC frequency affects these calculations in a somewhat complex manner. This program called AC Ohms Law makes calculating easy. Like my other program for just DC , select the value to solve for; either E, I, Z, R or XL. The program calculates various results using three inputs. The user can choose what to solve for based on whats known. Not sure what the value is just estimate and adjust it later.

A Glossary sheet helps you understand all variables. The inputs switch when you change the variables by just a little bit. This helps understand how the Equations work. All values change as you input values either by keyboard or UP/DN adjusters. The program warns for zero inputs and sets value to near zero. When your done just Email the results to your home base for review on any text editor or spreadsheet. This program is a must for Students and Engineers. It makes the complex understandable. Simply the best AC Ohms Law Calculator.


- AC Updates as You Edit
- AC Number Pad Digital Entry
- Displays a symbolic triangle of Z, XL, R and Pf
- AC Division by Zero warning
- AC Solve for E, I, Z, R or XL
- AC Calculates E,I ,R, XL, L, Pf and angle
- AC Circuit Diagrams showing delay in current.
- AC Help and Glossary with equations, Email

A home electrical system supplies current to an electric drill:
E = 113.5 [VAC] 60 [Hz] I = 2.80 [amps] R = 2.2 [ohms] If you solve for I using the DC equation I = E/R you get I = 51.59 [amps]. What Gives? In an AC circuit I = E/Z. Z is composed of a resistor equal to 2.2 ohms and an inductive coil in the motor L [henrys]. Select “Solve for XL” because we don’t know what the XL component of Z is. Input 113.5 [volts] for E, I = 2.8 [amps] and 2.2 [ohms] for R. The result is XL = 40.5 [ohms] inductive reactance with inductance = .107 [henrys]. Problem solved. The capacitance can be ignored. Look at the Power Factor Pf = .054 or 5 % or a 3.1 degree angle between the voltage wave and current wave which means that the circuit is mostly inductive. If an experiment was conducted with a pure resistor the power Factor would be near one or resistive.

Try solving for other variables using the adjuster buttons to see how the equations work. Check out the help and Glossary sheets.

This app was developed by Raymond Seymour. after working at General Electric for 37 years he’s now making Engineering apps for iOS. As an inventor he has over 60 granted US Patents.

iPhone Screenshots

(click to enlarge)

AC Ohm's Law by Ray Tools screenshot 1 AC Ohm's Law by Ray Tools screenshot 2 AC Ohm's Law by Ray Tools screenshot 3 AC Ohm's Law by Ray Tools screenshot 4

App Changes

  • March 04, 2014 Initial release