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A student investigates if lamps are brighter in a series circuit or a parallel circuit - OCR Gateway - GCSE Physics - Question 20 - 2020 - Paper 1
Question 20
A student investigates if lamps are brighter in a series circuit or a parallel circuit. He sets up two different circuits, A and B. State which circuit will have th... show full transcript
Worked Solution & Example Answer:A student investigates if lamps are brighter in a series circuit or a parallel circuit - OCR Gateway - GCSE Physics - Question 20 - 2020 - Paper 1
Step 1
State which circuit will have the brightest lamps
Answer
Circuit B, which is the parallel circuit, will have the brightest lamps. This is due to the fact that in a parallel circuit, each lamp receives the full voltage from the power source, allowing them to operate at their maximum brightness. In contrast, in a series circuit (Circuit A), the voltage is divided among the lamps, resulting in lower brightness for each lamp.
Step 2
Explain why
Answer
In a series circuit, if one lamp fails, the entire circuit is interrupted, causing all lamps to go out. Meanwhile, in a parallel circuit, even if one lamp fails, the other lamps will still receive voltage and remain lit. Thus, the parallel configuration not only leads to brighter lamps but also improves reliability.
Additionally, the current in a parallel circuit is higher, contributing to the brightness of the lamps. With the total current from the power source being split among the branches, each lamp still receives adequate current.
Step 3
Include the variables that the student needs to control
Answer
The student should control the following variables to ensure a fair experiment:
- Voltage of the power supply: The same voltage should be used for both circuits.
- Type and rating of the lamps: All lamps should be identical in brand and specifications to ensure uniform brightness.
- Wiring: The wire used for both circuits should be of the same gauge to ensure that resistance is consistent.
- Environmental conditions: The experiment should be conducted under similar light conditions to accurately assess brightness.