NEIEP Mechanics Practice Exam

How do you calculate the resistance in a series circuit?

1. By adding the individual resistances

2. By taking the average of the resistances

3. By multiplying the resistances

4. By dividing the highest resistance by the total current

The correct answer is: By adding the individual resistances

In a series circuit, the total resistance is calculated by adding the individual resistances together. This is because the same current flows through each component in a series arrangement, meaning that each resistor contributes to the overall resistance faced by the current. The formula for this is straightforward: R_total = R1 + R2 + R3 + ..., where R1, R2, R3, etc., are the resistances of the individual resistors. This addition occurs because, in a series circuit, each resistor acts as a barrier to current flow, and the total resistance is simply the sum of all these barriers. Thus, the correct approach is to add the values, which correlates directly with Ohm's Law, indicating how resistors in series affect circuit behavior.