Which capacitor type is likely to be used when space is a constraint but higher capacity is desired?

The selection of a capacitor type in scenarios where space is limited and a higher capacitance is required is best represented by electrolytic capacitors. These capacitors are designed to provide significant capacitance values in a relatively compact form, making them ideal for applications where size constraints are a factor.

Electrolytic capacitors utilize an electrolytic solution to form a dielectric layer and typically have a much higher capacitance per volume compared to other types of capacitors. This characteristic allows them to fit into smaller spaces while still providing the necessary energy storage.

In contrast, ceramic capacitors, while small, generally have lower capacitance values and may not suffice for applications requiring higher capacity. Film capacitors also tend to be larger for equivalent capacitance levels and are typically used in applications requiring stability and lower losses rather than high capacitance in small sizes. Oil-filled capacitors, designed for high voltage applications and stability, are even larger and unsuitable for constrained spaces.

Thus, the best choice for situations needing a higher capacitance in limited space is undeniably the electrolytic capacitor.