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Ohm's Ω Law

iPhone / iPad
  • Utilities
  • Reference
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Simply the best Ohm’s Law calculator. Solve for E, I or R and calculate power. Don’t know which to solve for? (It’s the one that you don’t have an entry for.) Still don’t know? Simply adjust inputs using the UP/DN arrow keys or touch the entry boxes for the keyboard. Need to switch which value to solve for? The inputs switch when you change the solve for selector. The formula changes as you select the variable.

See how Ohm’s law really works by using the UP/DN adjustors to change the variables by just a little bit. View instantaneous E,I,R and power calculations. Warns for division by zero and sets value to near zero.

Ω Updates as You Edit
Ω Number Pad Digit Entry
Ω Division by Zero Warning
Ω Solve for E, I or R

Solve for the correct resistor for example for powering an LED. Power supply volts (12) minus (2) volt LED drop is (10) volts with (.020) amps LED current results in (500) ohm’s resistor, but the nearest standard value is 470 or 510 ohms. Adjusting to 470 ohm’s and solving for current results in (.021) amps. A good design with just the touch of a few button.

Try it, It’s simply the best!

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.