Summarizing Ohm’s Law: Resistance and Simple Circuits

Summary

• A simple circuit is one in which there is a single voltage source and a single resistance.
• One statement of Ohm’s law gives the relationship between current \(I\), voltage \(V\), and resistance \(R\)in a simple circuit to be \(I=\cfrac{V}{R}.\)
• Resistance has units of ohms (\(\text{Ω}\)), related to volts and amperes by \(1 \Omega =\text{1 V/A}\).
• There is a voltage or \(\text{IR}\) drop across a resistor, caused by the current flowing through it, given by \(V=\text{IR}\).

Glossary

Ohm’s law

an empirical relation stating that the current I is proportional to the potential difference V, I ∝ V; it is often written as I = V/R, where R is the resistance

resistance

the electric property that impedes current; for ohmic materials, it is the ratio of voltage to current, R = V/I

ohm

the unit of resistance, given by 1Ω = 1 V/A

ohmic

a type of a material for which Ohm's law is valid

simple circuit

a circuit with a single voltage source and a single resistor