Parallel Plate Capacitor: Practice Problem & Solution
Ten capacitors are joined in parallel and charged with a battery up to a potential V. They are then disconnected from the battery and joined in series. Then, the potential of this combination will be:
Solution Explained:
To solve this problem, we apply the core principles of Parallel Plate Capacitor. Understanding the underlying formula is key to arriving at the correct answer below:
Let's analyze the problem step by step and derive why the potential difference is 10 V.
1. Capacitors in Parallel (Initial Condition)
When the 10 capacitors, each with capacitance
, are connected in parallel:
- The equivalent capacitance is:
- The total charge stored when connected to a battery of potential
is:
2. Capacitors in Series (Reconfigured System)
After disconnecting the battery, the capacitors are joined in series:
- The equivalent capacitance for 10 capacitors in series is:
- The charge
stored on the series combination remains the same (as charge is conserved):
3. Potential Across the Series Combination
The potential difference across a capacitor or combination of capacitors is related to the charge
and capacitance
:
Substitute
and
:
Thus, the potential across the series combination is
,.
Final Answer:
The potential of the series combination is:
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