An analogy for Ohm's
Law
Ohm's Law also make intuitive sense if you
apply if to the water-and-pipe analogy. If we have a water
pump that exerts pressure (voltage) to push water around a
"circuit" (current) through a restriction (resistance), we
can model how the three variables interrelate. If the
resistance to water flow stays the same and the pump
pressure increases, the flow rate must also increase.
If the pressure stays the same and the
resistance increases (making it more difficult for the water
to flow), then the flow rate must decrease:
If the flow rate were to stay the same while
the resistance to flow decreased, the required pressure from
the pump would necessarily decrease:
As odd as it may seem, the actual
mathematical relationship between pressure, flow, and
resistance is actually more complex for fluids like water
than it is for electrons. If you pursue further studies in
physics, you will discover this for yourself. Thankfully for
the electronics student, the mathematics of Ohm's Law is
very straightforward and simple.
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REVIEW:
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With resistance steady, current follows
voltage (an increase in voltage means an increase in
current, and visa-versa).
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With voltage steady, changes in current
and resistance are opposite (an increase in current means
a decrease in resistance, and visa-verse).
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With current steady, voltage follows
resistance (an increase in resistance means an increase in
voltage).
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