Final answer:
The current remains constant in a series circuit despite the opposition of resistors because the voltage source compensates for the increased total resistance with a higher voltage, according to Ohm's law (V = IR).
Step-by-step explanation:
If a current flows through a resistor in a series circuit, the resistor does oppose the flow of charges, which is the characteristic function of the resistor. However, in a series circuit, the current flowing through each resistor and across the entire circuit remains constant. This is because the total charge flowing per unit time does not decrease as it passes through the resistors—it simply faces more resistance, which the voltage source must overcome.
According to Ohm's law, the potential drop V across a resistor when a current flows through it is calculated using the equation V = IR, where I is the current in amps (A) and R is the resistance in ohms (Ω). As the resistors are arranged in series, their individual resistances add up to increase the total resistance of the circuit. The battery or voltage source provides enough electromotive force to push the charges through the higher resistance, ensuring the same amount of current flows through each component in the series.
Thus, although adding resistors in series to the circuit increases the total resistance, the current supplied by the battery depends on the equivalent resistance. The voltage source must increase the voltage to match the larger load to maintain a constant current flow. Essentially, the increase in resistance is offset by a proportionate increase in voltage applied to the circuit, keeping the current constant throughout the circuit.