The voltage drop over a resistor is proportional to the current running through it.

**I = E / R** says smaller resistance means more current.

**R = E / I** says find resistance with a test current.

**1 / R** is called conductance.

### Factoids

Samuel Morse couldn't get his telegraph to work over any distance until a physicist helped him figure out this relationship. With more wire (R), he needed more volts (V) to get the current (I) that his telegraph needed to work.

Many people find it helpful to think of volts like pressure and current like flow through various diameter hoses impeding fluid motion like resistors resist current.

Carver Mead extended the fluid analogy to Field-Effect Transistors by imaging water vapor spilling over a dam with varying headwaters. To make the analogy work he needed to imagine a planet with much stronger gravity. But, hey, its a thought experiment.