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Measuring current and voltage
Figure 3.7 The meter connected to a different part of the circuit. The effect is
the same as long as the red lead is correctly connected
in the opposite direction (think about it!) so the two things
mean the same. However, it does mean that we must define
which sort of current we are talking about when we use the
term. Figure 3.8 defines it graphically: conventional current
(usually called simply current) flows from positive to negative;
electron current flows from negative to positive. Whenever we
talk about current from now on, you should take it to mean
conventional current.
A meter with potential
Of course, your multi-meter can measure voltage, too. But
how should it be connected into the circuit to do it? Well, the
answer is that you don’t connect it into the circuit — because
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