BASIC ELECTRICITY 1
A
simple analogy will help you to understand electricity. Think of liquid
mud being pumped around a set of pipes. The pump produces a certain
pressure, causing mud to flow at a certain rate. The higher the
pressure, the faster the flow, and the narrower the pipes, the slower
the flow.
As you know from primary school, mud pressure is
measured in yurtzels and mud flow is measured in cubic ugbeks per
pipsqueak. But we don't use those units with electricity. Instead of
pressure we have voltage,
measured in volts (V). Instead of mud flow we have current,
measured in
amps (A). Instead of narrow pipes, we have resistance,
measured
in ohms (there's no ohm key on this typewriter, so I'll just have to
spell it
out).
An amp is rather a lot of
current, so in electronics we
use milliamps (mA, 0.001 A) or microamps (uA, 0.001 mA). Also an ohm
is a really tiny resistance, so we use kilohms (k ohm, 1000 ohms) or
megohms (M ohm, 1000 k ohms). Luckily, volts are just about the right
size, so we leave them as they are.