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226 6 Answers, Hints and Solutions
A5.5 See Fig. A.19.

(a) (b)
10 -10
d=100 nm j = 0, j =10 mV
1
2
j =30, j =30 mV
1
2
10 -11 d=40 nm 120 j =10, j =30 mV
2
1
d=20 nm j =10, j =-30 mV
1
2
Electrostatic force (N) 10 -13 j =10 mV Electrostatic force (N) 80
-12
10
=0 mV
j 1
2
40
-14
10
-15
10
0
10 -16
10 -17 -40
1 10 100 1,000 0 2 4 6 8 10
Distance (nm) Distance (nm)
Fig. A.19. Electrostatic force dependence on distance between particle and wall