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1. Figure 1 shows the results from an experiment where the potential difference (voltage) across a filament lamp was varied - Edexcel - GCSE Physics Combined Science - Question 1 - 2021 - Paper 1
Question 1
1. Figure 1 shows the results from an experiment where the potential difference (voltage) across a filament lamp was varied. The current and voltage were measured.... show full transcript
Worked Solution & Example Answer:1. Figure 1 shows the results from an experiment where the potential difference (voltage) across a filament lamp was varied - Edexcel - GCSE Physics Combined Science - Question 1 - 2021 - Paper 1
Step 1
Describe the relationship between the current and the voltage as shown in the graph in Figure 1.
Answer
The graph shows a positive correlation between the current and voltage. As the potential difference (voltage) increases, so does the current. However, the increase in current does not occur at a constant rate; the gradient of the graph decreases as voltage increases, indicating that the relationship is non-linear and not directly proportional.
Step 2
Step 3
Step 4
Explain why the resistance of the filament lamp changes as the voltage increases.
Answer
The resistance of the filament lamp changes with increasing voltage due to the heating of the filament as the current passes through it. As the temperature rises, the atoms within the filament vibrate more vigorously, which impedes the flow of electrons, thereby increasing the resistance. This phenomenon is typical for metallic conductors, where resistance increases with temperature.