hey.
you'll have to learn with understanding, and not just applying the
formular.
V=IR
So for anything that has a higher resistance, in order to conduct
current, the voltage difference had to increase.
Current is dangerous and inefficient, as current can easily kill
people, and when you're "transmitting" huge amount of current,
there's always the problem of heat loss, which is equalivant to
power loss, hence inefficient.
So pratical sense, current is usually the constant.
Applying to everyday life, you see those power stations, etc, they
always have "HIGH VOLTAGE" sign.
If the voltage difference is high enough, current can even be
transmitted through air.
