)
This shows that 1F is too big a unit in practice, as remarked earlier Another way of seeing the ‘bigness’ of 1F is to calculate the area of the
plates needed to have C = 1F for a separation of, say 1 cm:
0
Cd
A
=ε
=
2
9
2
12
2
–1
–2
1F
10
m
10 m
8 85
10
C N m
−
×−
=
×
(2 45)
which is a plate about 30 km in length and breadth