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Figure 6.1

7. The Correlation between Strength and Potential of Electric

Field

Let's consider transferring positive point charge at a rather small

distance dx from point 1 to point 2 (Fig. 7.1), where the force F  q  E
is assumed as constant (Fig. 7.1), then the work performed by electric
field is equal to

Figure 7.1

dA  F  dx  qEdx (7.1)

Suppose that equipotential surfaces with potentials  and   d 
pass through points 1 and 2 (dots lines) that is why it is obvious from

(5.1)

dA  q    d    qd  (7.2)

Comparing this equation and (7.1) gives:

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