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Alternating Current — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsAlternating Current3 Marks
Question
  1. A parallel plate capacitor $(C_1)$ having charge Q is connected, to an identical uncharged capacitor $C_2$ in series. What would be the charge accumulated on the capacitor $C_2?$
  2. Three identical capacitors each of capacitance 3mF are connected, in tern, in series and in parallel combination to the common source of V volt. Find out the ratio of the energies stored in two configurations.
✓

Answer

  1. Zero.
  2. We have $\text{C}_{series} = \frac{3\mu\text{F}}{3} =1 \mu\text{F}$
Also, $\text{C}_{parallel} =( 3 + 3 +3 ) =9 \mu\text{F}$

Energy stored $ = \frac{1}{2}\text{CV}^{2}$

$\therefore$Energy in series combination $ =\frac{1}{2}1 \times10^{-6}\times\text{V}^{2}$

Energy in parallel combination $ =\frac{1}{2}9 \times10^{-6}\times\text{V}^{2}$

$\therefore$ Ratio = 1:9.

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