# Voltage reference direction

1. Jun 8, 2013

### cytochrome

I see a lot of voltage drops being represented as an arrow. Say a voltage of 20V is represented as an arrow from point a to point b.

What is the polarity of and b then? Do the arrows to represent voltage usually go from + to - or from - to +?

Thanks for your time.

2. Jun 8, 2013

### sunrah

By convention the arrows represent a positive change in potential so they point to the higher voltage.

3. Jun 8, 2013

### cytochrome

I'm still trying to make sure I really understand this. Can someone answer my example question?

Say a voltage of 20V is represented as an arrow from point a to point b. What is the polarity of a and b then?