In a series circuit, what is true about current and voltage distribution?

• A. Different current in each component; voltage is the same across all
• B. The same current flows through all components; voltage divides among components in proportion to resistance
• C. Current is zero; voltage is constant
• D. Current doubles with more components; voltage remains constant

Answer: (B)

In a series circuit, the current has only one path to flow, so the same amount of current passes through every component. The total supply voltage is shared among the components, and how much each one drops depends on its resistance: the voltage across a component equals the current times its resistance (V = IR). Because the current is the same through all components, the voltages add up to the source voltage, and each component gets a portion proportional to its resistance. For example, if two resistors in series have resistances 2 Ω and 3 Ω with a 12 V source, the total resistance is 5 Ω, the current is 12/5 = 2.4 A, and the voltages are 4.8 V across the 2 Ω resistor and 7.2 V across the 3 Ω resistor, matching their resistance ratio.

That’s why the statement describing a series circuit—same current through all components, with voltage dividing among them in proportion to their resistance—best captures the behavior. The other ideas don’t fit: in series the current isn’t different across components, it isn’t zero unless the circuit is open, and adding more components doesn’t make the current increase while voltage remains constant.