Understanding Circuit Basics: The Role of Resistors in Simple Current

[ichigo444]

Is current constant throughout a simple circuit? So basically, what does the resistor do in a circuit?

 

[AJ Bentley]

It restricts the flow of electricity - just like an obstruction in a pipe.

No matter how big your pipe, if there is an obstruction, you only get a trickle out the end.

 

[sophiecentaur]

The resistance of a circuit element transfers some power into heat. Some of the total potential difference from the supply is dropped across the resistor as power is transferred. The amount of power 'dissipated' is given by the volts dropped X the current.
I don't like referring to it as a 'restriction' because that could also be achieved with a voltage generator, connected in reverse. In the case of a Resistor, Energy is lost.
Avoid waterflow analogies like the plague. They can lead to huge misconceptions.