Final answer:
The question asks for the capacitance between a set of conductors which can involve calculations based on their geometry and the use of dielectric materials.
Step-by-step explanation:
The question is asking for the capacitance between terminals a and b of different capacitive systems. Capacitance is a measure of a capacitor's ability to store charge per unit voltage. The formulas used to calculate capacitance vary depending on the geometry of the conductors and the presence of a dielectric material.
For the first case with two concentric spheres without a dielectric, the formula that should be used is based on the geometry of concentric spheres. For the other cases, the formula Q = CV is used, where Q is the charge, C is the capacitance, and V is the voltage. Adjustments will have to be made for the presence of a dielectric material. In all scenarios, it is crucial to understand that capacitors can be connected in either series or parallel, affecting the total capacitance.