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The graph shows the variation of potential difference (pd) with charge for a capacitor while it is charging - AQA - A-Level Physics - Question 25 - 2018 - Paper 2
Question 25
The graph shows the variation of potential difference (pd) with charge for a capacitor while it is charging. Which statement can be deduced from the graph? A. The ... show full transcript
Worked Solution & Example Answer:The graph shows the variation of potential difference (pd) with charge for a capacitor while it is charging - AQA - A-Level Physics - Question 25 - 2018 - Paper 2
Step 1
A. The charging current is constant.
Answer
The graph shows a linear relationship between potential difference (pd) and charge. This does not indicate that the charging current is constant, as the charging current would typically decrease as the capacitor charges. Therefore, this statement is not correct.
Step 2
B. The energy stored in the capacitor increases uniformly with time.
Answer
The energy stored in a capacitor is given by the formula , where is the energy, is the charge, and is the potential difference. The relationship in the graph implies that energy does not increase uniformly over time, as the charging process isn't linear. Thus, this statement is also incorrect.
Step 3
C. The capacitance of the capacitor is constant.
Answer
The relationship between pd and charge determined from the graph suggests a linear characteristic, indicating that capacitance (defined as ) remains constant. This statement aligns with the characteristics of a capacitor and is therefore correct.
Step 4