Equations · Physics
Ohm's law
The voltage across a resistor equals the current through it times its resistance.
V = IR
Aethel says
V equals I R
What it says
For a given resistance, doubling the voltage doubles the current. It is the starting point for analysing any electric circuit.
Symbol by symbol
| Symbol | Say it | Means |
|---|---|---|
| V | V | the voltage, in volts |
| I | I | the current, in amperes |
| R | R | the resistance, in ohms |
Where you meet it
Physics and electrical engineering.
Questions
How do you say Ohm's law out loud?
V = IR is read: “V equals I R.” That is exactly what Aethel says when it meets the formula in a book.
What does V mean in Ohm's law?
V (said “V”) is the voltage, in volts.
What does I mean in Ohm's law?
I (said “I”) is the current, in amperes.
Can I listen to the equations in my own textbook like this?
Yes. Upload a PDF, EPUB or text file and Aethel reads it aloud with every equation spoken as maths, the way it reads this one, and highlights each sentence as it goes. You can start free.