Find the potential difference between the points A and B in the circuit shoun in.
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Answer

`10 V`

Explanation

We assign node `N_(3)` as `0 V` and `N_(1),N_(2)` as `x,y` volt, respectively.
Condervation of charge in isolated system `1`.
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`5(y-0)+10(y-20 )+10[(y+20)-20]`
`+5[(y+20)-(-10)]=0`
or `30y=50` or `y=5/(3)V`
Conservation of charge in isolated system `2`.
`5[(x+20)-0]+10[(x+20)-10]+5[x-10]`
`+10[x-(-10)]=0`
or `30x=-250` or `x=(-25)/3V`
Thus, `V_(A)-V_(B)=5/3-((-25)/3)=10 v`
When switch ism closed, then potentials of `a` and `b` will be equal to `100 V`. Thus, initial charge and final charge distribution on all the plates is show in figure. Figure shows charugh switch is `300 muC`.