In a series circuit, how does the current vary along the conductor?

In a series circuit, how does the current vary along the conductor?

• A. Varies along the circuit with the resistance of each component
• B. Concentrated at the power source
• C. Zero after the first component
• D. Is the same everywhere

Answer: (D)

In a series circuit, the same current flows through every component because charge that leaves the source must pass through each element in turn. The current is the rate of flow of charge, and in a single closed loop there's only one path, so the amount passing any point per second is constant. The voltage across each component can differ, determined by V = I R for that element, so larger resistances take bigger voltage drops, but they don’t change the amount of current flowing. The overall current is set by the source voltage and the total resistance: I = V_source / R_total. So the current is the same everywhere along the conductor. It isn’t concentrated only at the power source, it isn’t zero after the first component, and it doesn’t vary along the circuit with the resistance of individual components.

In a series circuit, the same current flows through every component because charge that leaves the source must pass through each element in turn. The current is the rate of flow of charge, and in a single closed loop there's only one path, so the amount passing any point per second is constant. The voltage across each component can differ, determined by V = I R for that element, so larger resistances take bigger voltage drops, but they don’t change the amount of current flowing. The overall current is set by the source voltage and the total resistance: I = V_source / R_total. So the current is the same everywhere along the conductor. It isn’t concentrated only at the power source, it isn’t zero after the first component, and it doesn’t vary along the circuit with the resistance of individual components.