Air "breaks down" when the electric field strength reaches 3×10^6N/C, causing a spark. A parallel-plate capacitor is made from two 4.3 cm × 4.3 cm plates.

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Step 1:

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The electric field strength between the parallel plates is $\"\"$ .

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Dimensions of the two parallel plates is $\"\"$ .

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Find the number of electrons transferred from one plate to another.

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Total Charge $\"\"$ , where

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$\"\"$ is the number of electrons.

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$\"\"$ is the electron charge( $\"\"$ ).

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Therefore, $\"\"$ .

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Step 2:

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Find the total charge on the two plates.

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Total charge $\"\"$ , where

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$\"\"$ is the capacitance of the two plates $\"\"$ .

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$\"\"$ is the voltage across the parallel plates $\"\"$ .

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$\"\"$

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Here $\"\"$ is the area of the plate $\"\"$ .

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$\"\"$ is the permittivity of free space $\"\"$ .

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$\"\"$

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$\"\"$

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Find the number of electrons.

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$\"\"$

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$\"\"$

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Solution:

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$\"\"$

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