Year 9 - Science
Comparing series and parallel circuits
Resistance and parallel circuits
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit covers electrical circuits, compares appliance power ratings, and understands domestic fuel use and costs. It explores electric current, potential difference, resistance, and the differences between conductors and insulators, focusing on calculations and applications in circuits.
Lesson Summary
You will learn to compare the properties of series and parallel circuits that have the same components.
Key Notes
- With the same battery, two bulbs in parallel are brighter than two in series.
- With the same battery, current through two bulbs in parallel is bigger than through two in series.
- With the same battery, voltage across one of two bulbs in parallel is bigger than across one of two bulbs in series.
- With the same battery, two bulbs in parallel are transferring energy from the battery more quickly than two in series.
- A battery lighting two bulbs in parallel will run out faster than the same battery lighting the two bulbs in series.
Vocabulary To Learn
- series circuit: a circuit with a single loop
- current: the rate of flow of charge in a circuit
- voltage: a measure of the 'push' an electrical cell will give to charges
- parallel circuit: a circuit with junctions that lead to separate loops
Common Mistakes To Avoid
- The battery produces a fixed sized current that splits between each branch of a parallel circuit.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
With the same battery, two bulbs in parallel are brighter than two in series. With the same battery, current through two bulbs in parallel is bigger than through two in series.
2. Define this scientific word and use it in context. 'series circuit'
a circuit with a single loop. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: The battery produces a fixed sized current that splits between each branch of a parallel circuit. Correction: Consider each branch of a parallel circuit as a separate series circuit connected to an identical battery, in which the total current through the battery is determined by the current it can push through each of the branches added together.
More Lessons In This Unit
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