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Laboratory work #32
THE RESEARCH OF ELECTROSTATIC FIELD

Aim of work: to get a pattern of equipotential and force lines of
the electric fields of different system of electric charges
Laboratory equipment: source of direct current, a set of

electrodes, dish water with coordinate grate, sensing fingers, null-
detector.
1. Electrostatic Field and its Characteristics
The electric force, like the gravitational force, is an action-at-a-

distance force. In fact, we can see that the range of electric force
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between two point charges is infinite, since F l/r and it approaches
zero only if r approaches infinity. Thus, a particular arrangement, or

configuration, of charges can have an effect on an additional charge,
placed anywhere nearby (or possibly anywhere in space).
The idea to determine the force, acting within space, was a

difficult one for early researchers, and a concept of a force field, or
simply a field, was introduced. A force field is one of the matter forms
with the help of which an interaction between charges is realized.

The concept of electric field was introduced by Michael Faraday.
A static electric field (also referred to as an electrostatic field) is an
electric field that does not vary within time. Static electric fields are
created by electrical charges that are fixed in space.

An electric field may be detected and studied by its action on the
other electric charges. For this purpose, we use test charges, quantity
and size of which are so negligible that they do not evoke redistribution

of charges, and hence do not generate the field that is researched.
2. The Electric Field Intensity
The electrostatic field exists between electric charges and does
not change in time, as it is stationary. This field acts motionless due to

the movement of electric charges.
The intensity of the electric field E is determined as a
quantitative force characteristics of the electric field action on

charges. The intensity of electric field is defined as

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