In a series circuit, the current is

• A. The same through every component.
• B. Different in each component.
• C. Proportional to the sum of resistances.
• D. Equal to the total voltage.

Answer: (A)

In a series circuit, the current is the same through every component because there is only one path for the charges to flow, so the same amount of charge per second passes any point in the loop. The overall current is set by the source voltage and the total resistance: I = V_total / R_total. While the current is the same everywhere, the voltage across each component can be different, with V_i = I R_i, so the voltage drops add up to the total supply voltage. If the current varied from one component to another, charge would have nowhere to go at a junction, which isn’t possible in a steady loop. The other statements mix up the roles: current is not proportional to the sum of resistances, and it is not equal to the total voltage. The total resistance controls the current, and the voltage is what drives that current.