A student constructs a simple series circuit consisting of an ideal battery of emf 9.0 V and a 120 Ω resistor connected by conducting wires. Beginning at the negative terminal of the battery, the student moves clockwise around the circuit and sketches a graph of electric potential V versus position along the path. The sketch shows a sudden increase of 9.0 V across the battery followed by a linear decrease across the resistor back to the starting potential.
Use this information to respond to the following prompts.
(1) Identify which portion of the potential-versus-position sketch corresponds to the battery and which portion corresponds to the resistor. Explain your reasoning based on how each element affects the potential of the charge carriers.
(2) Describe why the total algebraic change in electric potential after one complete traversal of the circuit must be zero, even though individual elements change the potential.
(3) If the student instead chose to traverse the circuit counter-clockwise, describe qualitatively how the potential-versus-position graph would differ from the original sketch. Provide an explanation for the sign and shape of each segment in the new graph.