Armed with the simple quantities that we have looked at, we can now draw a simple circuit involving a voltage generator and a conductor, which has a defined resistance, R.
We can note some simple things from this diagram. We know that energy is being dissipated in the resistor and looking at the sense of the voltage and the current we can see that if the conventional current is flowing into the positive end of a voltage difference then this is equivalent to energy going into that part of the circuit (an energy sink). Conversely, if current is emerging from the positive end of a voltage difference then energy is coming out of this part of the circuit (an energy source).