Question

14a: A parallel plate capacitor (of area A and separation distance d) is initially charged bya battery with a potential difference of AV and is then disconnected from the battery. Adielectric of width L and dielectric constant ke is inserted into the capacitor (but doesn'tfill all of the space). Does the charge on the plates change? Explain. You may assume thateverything is essentially an infinite plane. b: Determine the new capacitance by using C = Q/AV. Does the expression give thecorrect results in the limit that L 0 and L d? Explain. c: Determine the ratio of the final energy stored to the initial energy stored. Does theexpression give the correct results in the limit that L 0 and L-→ d? Explain. d: Why doesn't the exact location of the dielectric matter here? e: Imagine that you did not disconnect the battery in this problem. Would your answers toparts a, b or c change? Explain.

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