Why is a F unit so big in practice ?

Explanation

For calculation of unit 1 F of capacitance, lettwo capacitors each has vacuum as medium between its plates separated by I cm distance.If the area A of each plates are same then, `C = (in_(0)A)/(d)`
`:. A = (Cd)/(in_(0))`
`=(1xx10^(-2))/(8.85xx10^(-12))`
`= 0.11299 xx10^(10)`
`:. A =1xx10^(9)m^(2)`
`= 10xx10^(8)m^(2)`
`:.` Length of side `=3xx10^(4)`
(If plates were square ) = 30 km is impossible to obtain in practice.