Question

The standard unit of capacitance is:
A. Farad
B. Ohm
C. Tesla
D. Ampere

Answer 1

Hint: A good point to begin with would be an understanding of what capacitance is in terms of a parallel plate capacitor and what factors it depends on. In other words, capacitance is given as (and depends on) the ratio of the charge and voltage on the capacitor.
Using this relation, we see that the base units of capacitance is $A^2s^4kg^{-1}m^{-2}$. This unit is compressed into the standard unit that is named after the English chemist who introduced the concept of dielectric constants and made capacitors a viable commercial technology.

Formula Used:
Capacitance $C = \dfrac{Q}{V}$, where Q is the electric charge of the conductor and V is the potential difference across the conductor.

Complete step by step answer:
Let us begin by first understanding what capacitance means.
Capacitance is a property of an electric conductor which determines the amount of electric charge that the conductor can hold when connected to a voltage source. In other words, capacitance of a conductor is dependent only on the geometry of the design (like the area of the plates and distance between them) and the permittivity of the dielectric medium between the plates of a capacitor. For most dielectric media, the permittivity, and thus the capacitance, is independent of the potential difference between the two plates or the total charge on them.
In circuits, the term capacitance is synonymous to mutual capacitance between two adjacent conductors. However, self-capacitance is the amount of electric charge that must be added to the conductor to raise its electric potential by 1 volt. Such a conductor is in general, called a capacitor.
Capacitors come in various shapes and sizes, such as parallel plates, concentric cylinders, concentric spheres, Circular discs or just a pair of parallel wires.
The energy stored in a capacitor is equal to the work required to push the charges into the capacitor. Thus, the work is done against the potential V in order to charge the capacitor to Q.
Thus, we can conclude that capacitance is the ratio of the electric charge of a conductor to its electric potential.
$\Rightarrow C = \dfrac{Q}{V} = \dfrac{coulomb}{volt} = farad$
Therefore, the correct choice would be: A. Farad.

Note:
Remember that capacitance for a parallel plate capacitor can also be expressed in an alternate form where it still has the same units:
$C = \epsilon_0 \dfrac{A}{d}$, where $\epsilon_0$ is the permittivity of free space, A is the surface area of the plates and d is the distance between the plates.
Also, the self-capacitance of a conducting sphere of radius R is : $C = 4 \pi \epsilon_0 R$.
Therefore, the capacitor’s capability to store charge is measured in Farads.