The unit of capacitance is

Analyze the question: You are asked for the SI unit used to measure capacitance, which is the ability of a component (a capacitor) to store electric charge.

Explain the concept: Capacitance is defined as the charge stored per unit potential difference:

C = Q / V

where

• C = capacitance
• Q = charge (in coulombs, C)
• V = potential difference (in volts, V)

So the unit of capacitance is coulomb per volt (C/V). This unit has its own name: the farad (F), after Michael Faraday.

1 farad = 1 coulomb per volt

Check each option:

• A. Farad: the unit of capacitance. Correct.
• B. Coulomb: the unit of electric charge, not capacitance.
• C. Henry: the unit of inductance (for coils/inductors).
• D. Ohm: the unit of resistance.

Answer: The correct option is A, farad.

Exam tip: Match each electrical quantity to its unit by remembering the pairs:

• Capacitance → Farad (F)
• Inductance → Henry (H)
• Resistance → Ohm (Ω)
• Charge → Coulomb (C)

A quick memory trick: "Farad for Capacitance," since both have the "a" sound, while "Henry" goes with "Inductance" (think of a coil, "H" for the "hoop" of wire).