The method
Before using the result
- Ideal positive resistors; no wiring resistance, temperature drift or power-rating assessment.
Worked examples
These original training examples illustrate the method for Journeyman Electrician Core Knowledge Review (JE). Use the matching “Load example” button above to explore a variation; example values are not equipment settings or prescribed criteria.
1. Worked example
Compare the same resistors connected in series and parallel. Check whether the equivalent must be larger than the largest resistor or smaller than the smallest.
- Connection
- Series
Supplied resistors
| Resistance (Ω) |
|---|
| 100 |
| 200 |
- Series connection: 100, 200 Ω.
- ΣR = 300 Ω.
- Equivalent resistance: 300 Ω
2. Comparison example
Compare a different supplied condition using the same method. For Electrical Exam, the important check is that the input meaning, units and method assumptions still match the problem.
- Connection
- Parallel
Supplied resistors
| Resistance (Ω) |
|---|
| 100 |
| 200 |
- Parallel connection: 100, 200 Ω.
- 1/Σ(1/R) = 66.66666666666667 Ω.
- Equivalent resistance: 66.66667 Ω
Check your understanding
1. Which relationship is used?
Series R = ΣRi; parallel R = 1/Σ(1/Ri).
2. Which assumption should you check first?
Ideal positive resistors; no wiring resistance, temperature drift or power-rating assessment.
3. How should you verify a different unit system?
Convert every input to the displayed calculation units first. Equivalent physical inputs must give equivalent results; a unit label alone does not convert a number.
Continue with the matching exam topic
This tool connects to Journeyman Electrician Core Knowledge Review (JE) free practice. Work through a question independently, then use the calculation steps to identify where your method differs. The tool stays free whether or not you choose paid preparation.