Does a Resistor Affect Current in a Circuit?

[lha08]

Homework Statement

I'm trying to understand how does a resistor in a circuit affect the current...like this is what I'm getting...when the resistance of a circuit increases, the current passing through it decreases? And its the same for the opposite; as the resistance decreases, there is more current passing through it...Is this right? Like I can't really picture why exactly this happens. Like i though that the particles don't lose charge as they pass through the resistor, just potential energy, but how does it affect current...??
Maybe the current does not change?

Homework Equations

The Attempt at a Solution

 

[espen180]

Resistors are simply made using high-resistivity materials.
http://en.wikipedia.org/wiki/ResistorAlso this thread does not belong here, it belongs in the appropriate physics/engineering forum.