Find the capacitance between A and B if two dielectric alabs (each of area `A`) of dielectric constants `K_(1)` and `K_(2)` and thicknesses `d_(1)` and `d_(2)` are inserted between the plates of a parallel plate capacitor of plate area `A`.
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Explanation

`C=(sigma a)/(V) , V=E_(1)d_(1)+E_(2)d_(2)=(sigma d_(1))/(K_(1)in_(0))+(sigmad_(2))/(K_(2)in_(0))=(sigma)/(in_(0))((d_(1))/(k_(1))+(d_(2))/(k_(2)))`
`:. C=(Ain_(0))/((d_(1))/(K_(1))+(d_(2))/(K_(2)))rArr(1)/(C)=(d_(1))/(AK_(1) in_(0))+(d_(2))/(AK_(2)in_(0))`
This formula suggests that the system between A and B can be considered as series combination of two capacitors.