Air "breaks down" when the electric field strength reaches 3 × 106 n/c, causing a spark. a parallel-plate capacitor is made from two 5.5 cm × 5.5 cm electrodes.

Electric field between the plates of parallel plate capacitor is given as

here area of plates of capacitor is given as

also the maximum field strength is given as

now we will plug in all data to find the maximum possible charge on capacitor plates

so the maximum charge that plate will hold will be given by above

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