Charge distribution with a dieilectric

Please show me the charges appearing on each faces. A dilelectric is kept inside two conductor as shown in figure.

11 Answers

1
seoni ·

this wil help
http://hermes.eee.nott.ac.uk/teaching/cal/h51emf/emf0017.html

21
Shubhodip ·

that does not helping at all, :D

please help

1
seoni ·

click on 4' at the bottom of that page

21
Shubhodip ·

that's fine.

but here the dielectric is kept in contact with the conductor(on the right side)

30
Ashish Kothari ·

I guess it should be like this.

21
Shubhodip ·

is it correct ?

30
Ashish Kothari ·

I guess it isnt. [3] Asked subho da ysterday..

49
Subhomoy Bakshi ·

The charge on the outer surface of the plates is 0 ....

The charge on the inner surface of the plates is ±KAεod+Kx.V for the respective plates..

The charge on the either surfaces of the dielectric slab is ±(K-1)Aεod+Kx.V ...

I will give solution tomorrow..

But these are the right answers according to me..

@Ashish: Try to prove the results!

30
Ashish Kothari ·

Thus if we calculate the equivalent capacitance for the series combination,

\frac{1}{C_{eq}}= \frac{x}{A\epsilon _{o}}+\frac{d}{AK\epsilon _{o}}

C_{eq}= \frac{AK\epsilon _{o}}{d+Kx}

Now, since in series combination, charge on both capacitors is same, we can say charge on first plate (connected to positive terminal of the battery) is

Q=\left( \frac{AK\epsilon _{o}}{d+Kx}\right)V

Similarly, charge on the capacitor with dielectric will be the same.

Now,

Q_{induced}=Q\left(1-\frac{1}{K} \right)

Therefore,

charge on the faces of the dielectric = \pm \left( \frac{A\epsilon _{o}}{d+Kx}\right)\left( K-1\right)V

But, I can't get why the charge on the outer faces of the capacitor plates becomes zero. [7]

49
Subhomoy Bakshi ·

@Ashish: Answer to your doubt: Coz if the charges were not zero the field inside the conducting plates would not have become zero!

30
Ashish Kothari ·

I get it now. [1] Finally!

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