Generator harder to crank if there is current.
More current, more harder.
Whah?
What's current?
That's a measure of current. What does that mean?
- Coulombs measure charge, seconds measure time intervals.
- So coul / sec measures charge / time interval.
What gotta be happening to get charge / time interval?
- Gotta have a transport of charge.
Why does that make it harder to crank?
- More force needed to push charge.
Why charge gotta be pushed?
- Charges keep runnin into things, gotta always be gettin
accelerated (not really; it comes down to wave mechanics and waves gotta keep
getting energized, but this isn't a bad model of overall understanding)
What pushes charge?
- electric field pushes charge by continually accelerating
the charges
- note that voltage is electric field * displacement (or sum
of electric field * displacement contributions, if electric field is variable
with position, more accurately integral of electric field * displacement)
Cranking a current thru a capacitor, cranking at constant
rate, it gets easier and easier to turn the crank. Why?
- Gotta be less current in the wire.
Why less current in the wire?
- Less electric field in the wire; alternatively less voltage
across the wire.
Why less field and less voltage?
- Capacitor builds charge opposing voltage of generator.
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