A capacitor consists of two concentric spherical shells. The outer radius of the inner shell is a=0.76 mm and the inner radius of the outer shell is b=3.31 mm .

(a) What is the capacitance C of this capacitor? Express your answer in Farads.

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(b) Suppose the Maximum possible electric field at the outer surface of the inner shell before the air starts to ionize is Emax(a)=3.0×106V⋅m-1 . What is the maximum possible charge on the inner sphere? Express your answer in Coulombs.

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(c) What is the maximum amount of energy stored in the capacitor? Express your answer in Joules.

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(d) When E(a)=3.0×106V⋅m-1 what is the absolute value of the potential difference between the shells? Express your answer in Volts.