200 Years of Ohm's Law: The Simple Formula That Changed Electrical Engineering
Date :
12 /
11 /
2026
Author :
René Lutz HB9NBG
E = I × R. Three letters, one simple equation, and 200 years of electrical and electronic innovation!
This year marks the 200th anniversary of the first publication of the scientific findings that became known as Ohm's Law, one of the most fundamental principles in electricity, electronics and amateur radio.
In 1826, German physicist Georg Simon Ohm published the results of his investigations into the relationship between electrical current, voltage and resistance. He expanded on this work in 1827 in his landmark publication, The Galvanic Chain, Mathematically Processed.
Today, Ohm's Law is familiar to almost everyone who has studied basic electronics:
E = I × R
Where E is voltage in volts, I is current in amperes and R is resistance in ohms (Ω).
From Scientific Discovery to the Radio Shack
What we can now explain in a few seconds represented a remarkable scientific achievement two centuries ago.
Ohm's research helped transform electricity from an experimental curiosity into something engineers could measure, calculate and use to design reliable equipment.
For radio amateurs, Ohm's Law remains an essential part of everyday experimentation.
Whether calculating the current drawn by a transmitter, selecting a resistor for an electronic circuit, troubleshooting a power supply or understanding antenna and transmission-line behaviour, Ohm's Law provides a foundation for practical RF engineering.
For example, a 100-watt transmitter drawing power from a 13.8-volt supply will require considerably more than 7.2 amperes because no transmitter is 100 per cent efficient. Ohm's Law and related electrical power calculations help us understand these practical requirements.
A Legacy That Continues
Interestingly, Ohm's original research was initially met with scepticism. Its importance was recognised only later, and the international unit of electrical resistance, the ohm (Ω), now bears his name.
Two centuries later, his work remains fundamental to modern telecommunications, electronics, computing and radio communications.
The anniversary was recently highlighted by Swiss radio amateur René Lutz HB9NBG, who reminded fellow amateurs of the continuing importance of Ohm's Law in our hobby.
For WIA-affiliated clubs, the anniversary provides a great opportunity for a technical presentation, practical electronics workshop or Foundation training session.
After 200 years, Ohm's Law is still helping radio amateurs turn electrical theory into practical experimentation.
Further Reading
Original LinkedIn article, René Lutz HB9NBG:
Link
Additional article shared by HB9NBG:
Link
Encyclopaedia Britannica: Georg Simon Ohm:
Link
Picture sourced from the Linked-In Story.
Acknowledgement: Inspired by the LinkedIn article “200 years of Ohm's law” by René Lutz HB9NBG, Lutz-Electronics KLG, Switzerland.
Page Last Updated: Wednesday, 11 Nov 2026 at 21:46 hours by Justin Giles-clark
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