In a series circuit, which quantity remains constant through all components?

In a series circuit, which quantity remains constant through all components?

• A. Voltage
• B. Current
• C. Power
• D. Resistance

Answer: (B)

Current remains constant through all components in a series circuit because charge has only one path to follow. The same amount of current that leaves the source must flow through each element in turn, so the current value is identical at every point around the loop. Voltage, however, is not constant; it is split among the components in proportion to their resistance, and the sum of those voltage drops equals the source voltage. Resistance varies by component, and while the current is the same through the series loop, different components can have different voltage drops and power dissipation (P = VI or P = I^2R). If one component opens the circuit, the current stops everywhere, showing that the current is shared across the entire series chain.

Current remains constant through all components in a series circuit because charge has only one path to follow. The same amount of current that leaves the source must flow through each element in turn, so the current value is identical at every point around the loop. Voltage, however, is not constant; it is split among the components in proportion to their resistance, and the sum of those voltage drops equals the source voltage. Resistance varies by component, and while the current is the same through the series loop, different components can have different voltage drops and power dissipation (P = VI or P = I^2R). If one component opens the circuit, the current stops everywhere, showing that the current is shared across the entire series chain.