NEIEP Mechanics Practice Exam

When dealing with resistors in series, how does the total resistance compare to the individual resistances?

1. It is less than the smallest resistor

2. It is equal to the sum of all individual resistances

3. It remains unchanged

4. It cannot be determined

The correct answer is: It is equal to the sum of all individual resistances

When resistors are connected in series, the total resistance is indeed equal to the sum of all individual resistances. This occurs because, in a series circuit, the current flowing through each resistor is the same. Each resistor presents its own opposition to the flow of current, so the total opposition is additive. For instance, if you have two resistors with resistances of 5 ohms and 10 ohms in series, the total resistance would be calculated as follows: 5 ohms + 10 ohms = 15 ohms. This additive property is a fundamental aspect of electrical circuits when resistors are arranged in series. Consequently, the total resistance will always be greater than the resistance of any single resistor in the series, as it accounts for all resistances combined. Thus, the correct answer reflects this important principle in circuit analysis.