Final answer:
The charge on the 4.20-µF capacitor in series with two other capacitors can be calculated by finding the total capacitance in series and then using the relation Q = Ctotal × V. When reconnected in parallel, the voltage across each capacitor will be the same as the source voltage, 36.0V.
Step-by-step explanation:
To find the charge on the 4.20-µF capacitor when connected in series with two 8.40-µF capacitors, we first determine the equivalent capacitance of the series combination. The reciprocal of the total capacitance in a series circuit is the sum of the reciprocals of the individual capacitances:Ctotal = 1 / (1/C1 + 1/C2 + 1/C3)
Once we have the total capacitance, we use the formula Q = Ctotal × V to find the charge, Q, because the charge is the same across all series capacitors due to the same amount of electrons being displaced. For the capacitors reconnected in parallel, each capacitor will have the same voltage across it as the original source voltage, because in a parallel circuit, all components share the same voltage. The voltage across each capacitor in the parallel combination will be 36.0 V.