In a series circuit, which statement is true?

In a series circuit, which statement is true?

• A. The current varies between components, and each component drops its own voltage.
• B. The current is the same through each component, and the sum of the voltages across components equals the source voltage.
• C. The current is the same through each component, and the voltage across each component is proportional to its resistance.
• D. The current is the same as the voltage across the first component.

Answer: (C)

In a series circuit, the same current flows through every component, and the voltage drop across each component follows Ohm’s law: V = I × R. Since the current is the same everywhere, each component’s voltage drop is proportional to its resistance. That means a larger resistance will drop more voltage, and when you add up all the individual drops, you get the source voltage. That makes the statement that the current is the same through each component and the voltage across each component is proportional to its resistance the best description of how a series circuit works. The idea that current varies between components is incorrect because there’s only one path for current. While it’s true that the voltages add up to equal the source voltage, that alone doesn’t specify how those drops relate to the components’ resistances. And current and voltage are different quantities, so saying the current is the same as the voltage on the first component isn’t accurate.

In a series circuit, the same current flows through every component, and the voltage drop across each component follows Ohm’s law: V = I × R. Since the current is the same everywhere, each component’s voltage drop is proportional to its resistance. That means a larger resistance will drop more voltage, and when you add up all the individual drops, you get the source voltage.

That makes the statement that the current is the same through each component and the voltage across each component is proportional to its resistance the best description of how a series circuit works. The idea that current varies between components is incorrect because there’s only one path for current. While it’s true that the voltages add up to equal the source voltage, that alone doesn’t specify how those drops relate to the components’ resistances. And current and voltage are different quantities, so saying the current is the same as the voltage on the first component isn’t accurate.