Apologies for this simple question, but I'm having trouble grasping the concept of how an ammeter works.
Taking the following circuit as an example:
When the switch is closed, current flows through the circuit - ie. there is a potential difference between the two ends of the circuit, so electrons flow from the negative terminal to positive.
The ammeter records the current flowing through the variable resistor.
My question is: How can the ammeter tell how much current is flowing the resistor? since it's "behind" the resistor?
And also: Why and how does a resistor limit the current flowing through the entire circuit? doesn't it limit only the current that is flowing past and after the resistor?