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Old 04-11-2015, 08:27 PM   #22
NN5I
Carl, nn5i
 
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Join Date: Sep 2011
Location: Tallahassee, FL
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Quote:
Originally Posted by W7JZE View Post
Any homework tonight, Teach?
Yup. Memorize the following:

A watt is a joule per second.

A volt is a joule per coulomb.

A volt is a coulomb per farad. Thus a farad is a coulomb per volt.

An ampere is a coulomb per second.

A henry is a volt per (ampere per second), i.e. a volt-second per ampere.

An ohm is a volt per ampere. Thus a mho is an ampere per volt.

Manipulate these to show that:

An ampere per second is a volt per henry. Understand this to mean that, to change the current through an inductor by one ampere per second (increasing or decreasing), you must impose one volt across the inductor for each henry of its inductance.

A watt is a volt-ampere.

A joule is a farad-volt-squared.

... and so forth.

Now then, how many joules are stored in a two-farad capacitor charged to three volts?
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