A spark can form when the electric eld in air becomes larger than 3.0 X 106 V/m. Suppose you have a parallelplate capacitor that uses uses circular plates of radius 5 .0 cm that are separated by a distance of 2.0 mm. How much charge would you need to put on the plates in order for a spark to form between them? (A value of Q means that the positive and negative plates are charged to +Q and Q, respectively.) A) 75 nC B) 210 nC C) 380 nC D) 590 nC E) 720 nC A photovoltaic cell uses sunlight to move electrons from the positive terminal of the cell to the negative terminal of the cell. The cell does 1.2 X 1019 J of work per electron. Suppose you connect the terminals of the cell to a resistor with a resistance of 18 Q. What will be the current through the resistor? A) 12 mA B) 28 mA C) 42 mA D) 57 mA E) 73 mA