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A 0.9 µF capacitor is charged to a potential difference of 10.0 V. The wires connecting the capacitor to the battery are then disconnected f
Question
A 0.9 µF capacitor is charged to a potential difference of 10.0 V. The wires connecting the capacitor to the battery are then disconnected from the battery and connected across a second, initially uncharged, capacitor. The potential difference across the 0.9 µF capacitor then drops to 2 V. What is the capacitance of the second capacitor?
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Physics
4 years
2021-09-03T14:58:40+00:00
2021-09-03T14:58:40+00:00 1 Answers
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Answer:
3.6μF
Explanation:
The charge on the capacitor is defined by the formula
q = CV
because the charge will be conserved
q₁ = C₁V₂
q₂ = C₂V₂ where C₂ V₂ represent the charge on the newly connected capacitor and the voltage drop across the two capacitor will be the same
q = q₁ + q₂ = C₁V₂ + C₂V₂
CV = CV₂ + C₂V₂
CV – CV₂ = C₂V₂
C ( V – V₂) = C₂V₂
C ( V/ V₂ – V₂ /V₂) = C₂
C₂ = 0.9 ( 10 /2) – 1) = 0.9( 5 – 1) = 3.6μF