Why do resistors get hotter when there is an electric current through them?
collisions between moving charges and stationary ions in the wire cause a heating effect
energy from the current is wasted as heat
Why does the potential difference across two or more components add up to the potential difference across the battery?
none of it is wasted
the work done in each unit of charge in the battery must equal the work done in the components
Why is the potential difference largest across the component with the most resistance?
more work is done by the charge moving through a large resistance than a smaller one
it takes more energy to move across a bigger resistance