BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 2
FIGURE 13.
THREE VARIABLES IN A BASIC CIRCUIT.
Figure 14 (on the following page) shows the graph and a table of values.
This table shows R held constant at 10 Ohms as E is varied from 0 to 20
volts in 5 volt steps. Through the use of Ohm's law, you can calculate the
value of current for each value of voltage shown in the table.
When the
table is complete, the information it contains can be used to construct the
graph shown in figure 14. For example, when the voltage applied to the 10
Ohm resistor is 10 volts, the current is 1 ampere. These values of current
and voltage determine a point on the graph. When all five points have been
plotted, a smooth curve is drawn through the points.
Through the use of this curve, the value of current through the resistor can
be quickly determined for any value of voltage between 0 and 20 volts.
Since the curve is a straight line, it shows that equal changes of voltage
across the resistor produce equal changes in current through the resistor.
This fact illustrates an important characteristic of the basic law--the
current varies directly with the applied voltage when the resistance is held
constant.
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