Kapasitassi

Kapasitassi is the Finnish term for capacitance, the property of a system to store electric charge per unit voltage. In physics and electrical engineering, capacitance is defined as C = Q / V, where Q is the stored charge and V is the potential difference between conductors. The unit is the farad (F).

For a simple capacitor, the energy stored is U = 1/2 C V^2, and the charge relates to voltage by Q = C V. In a parallel-plate capacitor, the capacitance can be expressed as C = ε0 εr A / d, with A the plate area, d the separation, ε0 the vacuum permittivity, and εr the dielectric’s relative permittivity.

Dielectrics increase capacitance by polarization in response to the electric field. Real capacitors use various dielectric materials to tailor C, voltage rating, and temperature stability. Capacitance can depend on frequency, temperature, and orientation in anisotropic dielectrics, and parasitic inductance and resistance affect high-frequency behaviour.

In circuits, capacitance determines time constants, such as τ = RC in RC circuits, and influences filtering and energy storage. Capacitors are common components with many types, including ceramic, film, electrolytic, and tantalum, chosen for voltage rating, size, and capacitance range.

Measuring capacitance typically involves LCR meters or impedance analysis. The term kapasitassi is used in Finnish-language texts to denote this quantity and is essential in electronics, power electronics, and signal processing contexts.