Final answer:
The SI unit for capacitance is the farad (F), a large unit signifying the stored electric charge per unit electric potential, with the formula 1 F = 1 C/V. Capacitance depends on the physical structure and properties, such as the area of the capacitor plates, the distance between the plates, and the permittivity of the medium.
Step-by-step explanation:
The SI unit for capacitance is the farad (F), which is named after Michael Faraday, a prominent English scientist known for his work in electromagnetism and electrochemistry. Capacitance is a measure of the amount of electric charge stored (or separated) for a given electric potential. Therefore, one farad is defined as the capacity to store one coulomb (C) of charge with one volt (V) of potential difference across the terminals of a capacitor. Formally, 1 F = 1 C/V. The farad is a large unit and is often used with prefixes to denote submultiples, such as microfarads (μF), nanofarads (nF), and picofarads (pF).
The practicality and size of a capacitor with a farad-level capacitance require significant physical dimensions, relying on factors such as the area of the plates (A) and the distance between them (d), as well as the permittivity of free space (ε₀). The equation for the capacitance of a parallel plate capacitor is given by C = ε₀ (A/d), where ε₀ = 8.85 × 10⁻¹² F/m, which shows the direct proportionality between capacitance and the plate area, and inverse proportionality to the distance between the plates.