Which quantity remains constant through all components in a series circuit?

Which quantity remains constant through all components in a series circuit?

• A. Voltage varies
• B. Resistance varies
• C. Current remains constant through all components
• D. Power varies

Answer: (C)

In a series circuit there is only one path for current, so the same amount of current flows through every component. That means the current is constant throughout the loop, even though the voltage drop across each component can differ depending on that part’s resistance (V = IR). The voltages add up to the source total, and each component’s resistance determines its share of the drop, while power dissipation varies from one component to another (P = VI = I^2R) because the resistance can be different. So the quantity that remains constant through all components is the current.

In a series circuit there is only one path for current, so the same amount of current flows through every component. That means the current is constant throughout the loop, even though the voltage drop across each component can differ depending on that part’s resistance (V = IR). The voltages add up to the source total, and each component’s resistance determines its share of the drop, while power dissipation varies from one component to another (P = VI = I^2R) because the resistance can be different. So the quantity that remains constant through all components is the current.