Three initially uncharged capacitors are arranged with batteries as shown in. Find the charge on each capacitor.
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Explanation

Let potential at A is 0, so at D it is 30 V, at F it is 10 V and at point G potential is -25V and let potential at E is x. Now apply kirchhoff,s `1^("st")` law at point E. (Total charge of all the plates connected to 'E' must be same as before i.e. 0)
`:. (x-10)+(x-30)2+(x+25)2=0`
`5x=20`
`x=4 V`
Final charges :
`Q_(2 mu F)=(30-4)2=52 mu C`
`Q _(1 mu F)=(10-4)=6 mu C`
`Q _(2 mu F)=(4-(-25))2=58 mu F`