The total resistance in a series circuit equals the sum of all individual resistances. Which description matches this circuit law?

The total resistance in a series circuit equals the sum of all individual resistances. Which description matches this circuit law?

• A. Law for current in a series circuit
• B. The total resistance in a series circuit equals the sum of all individual resistances
• C. Law for voltage in a series circuit
• D. Law for resistance in a parallel circuit

Answer: (B)

In a series circuit, the same current flows through every component, so the total resistance the source sees is simply the sum of the individual resistances. This means R_total = R1 + R2 + ... and the current is I = V / R_total, while the voltage across each resistor adds up to the total voltage (Vi = I × Ri and V = V1 + V2 + ...). For example, two resistors of 4 ohms and 6 ohms in series give a total of 10 ohms, and with a given supply, the current is determined by that total resistance. This description matches how resistance combines in series, which is different from how resistance behaves in parallel, where the reciprocal of the total resistance adds.

In a series circuit, the same current flows through every component, so the total resistance the source sees is simply the sum of the individual resistances. This means R_total = R1 + R2 + ... and the current is I = V / R_total, while the voltage across each resistor adds up to the total voltage (Vi = I × Ri and V = V1 + V2 + ...). For example, two resistors of 4 ohms and 6 ohms in series give a total of 10 ohms, and with a given supply, the current is determined by that total resistance. This description matches how resistance combines in series, which is different from how resistance behaves in parallel, where the reciprocal of the total resistance adds.