Question

Constants Part A A parallel-p ate capacitor with only air between the plates is charged by connecting it to a battery. The capacitor is then disconnected fram the battery, without any of the charge lcaving the plates A voltmeter reads 46.0 V when placed across the capacitor. When a dielectric is inserted between the plates, completely filing the space, the voltmeter reads 13.0 V. What is the dielectric constant of this material? Submit Part B what will the voltmeter read I「the dielectric Is now pulled partway out so trls only one-third ot the space between the pates? Submit Return to Assignment Pode Feedback

Answer 1

Solution)

Part a)

Vo = 46 volts

V = 13 volts

We know,

dielectric constant k = k Co

The potential with dielectric V= Q / C = Q / k Co

Now, The potential without dielectric will be, Vo = Q /Co

So, k=Vo/V=46/13 = 3.53 (Ans)

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Part b)

Here,

C1= KCo / 3 and C2 = 2 Co /3

Here, two capacitors are parallel

So,Ceq = C1 + C2

Ceq = (Co / 3)(k + 2)

V = Q /Ceq = Q / Co(3 / k + 2) =Vo(3 / k + 2)

V =46 volts (3 /5.53) = 39 volts

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