Final answer:
The maximum charge that can be added to the plates of a parallel-plate capacitor without causing a spark to jump between them is approximately 60,000 C.
Step-by-step explanation:
The maximum charge that can be added to the plates of a parallel-plate capacitor without causing a spark to jump between them can be determined using the formula Q = CV, where Q is the charge, C is the capacitance, and V is the potential difference. In this case, the potential difference is given as 3 x 10^6 N/C, and the capacitance can be calculated using the formula C = eoA/d, where eo is the permittivity of free space, A is the area of the plates, and d is the separation distance between the plates.
Given that the area of each plate is 0.02 m² and the separation distance is 0.01 m, we can substitute these values into the formula C = eoA/d to find the capacitance. Then, we can use the formula Q = CV to calculate the maximum charge that can be added to the plates.
Therefore, the maximum charge that can be added to each of the plates before a spark jumps between them is approximately 60,000 C.