Physics · Electricity · Magnetism / Principles and Exploration
Series and parallel circuits — principles and investigation
Even if two identical resistors are connected, the current flowing from the power source will vary depending on how they are connected. Change the series and parallel connections and compare the equivalent resistance and the voltage, current, and power of each resistance. If you look at the point where the current diverges and the potential difference, you can check the meaning of the memorized formula on the circuit diagram.
How does it work?
In series, the current is the same, and in parallel, the voltage is the same.
Series R = R₁+R₂ · Parallel 1/R = 1/R₁+1/R₂
Try this investigation
- Change the connection method and switch in the fixed circuit. In series, the current is the same and the voltage is divided. In parallel, the voltage is the same and the current is divided.
- Press the standard conditions button, run it, and record each measurement value.
- Compare the equivalent resistance and current by changing the connection method at the same voltage. When the switch is opened, the current and resistance voltage are 0.
Interpreting your results
What is the relationship between total current and branch current in a parallel circuit?
The current coming from the branch point is equal to the sum of the two currents.
Assumptions and limitations
Assume that the resistance of the wire, power supply, and ammeter and the internal resistance of the battery are 0. Temperature changes and transient phenomena in resistance are omitted. We only deal with fixed two resistance circuits.