Wednesday, March 26, 2008

3/26/08 Class Notes

AC = alternating current. The flow of the current alternates direction
DC= direct current. Only flows in one direction
We will only be working with DC.

Current (I)= the flow of an electric charge. Unit: ampere (A) or coulomb/second.
The equation for current is listed in the reference table as I=(change in q)/(t)

Potential difference (V)= the driving force behind causing a flow of charge.
SI Unit: volt (V)
1 V=1 J/C
The equation to find V is V = W/q

Resistance (R)= oppostition to the flow of the current. It measures the degree and object opposes a current
SI Unit: ohm (theres a funky symbol in the reference table for it) which was named after a German physicist

Ohm's Law: At Constant Temperature, The Current In A Metallic Conductor Is Directly Proportional To The Potential Difference Between Its Ends.

The equations for Ohm's law are as follows... R=V/I....I=V/R.....V=IR
1 ohm = 1 Volt/Amp

We did two exaples in class and then worked on homework for the time we had left.

4 comments:

lucien said...

this blog helped describe the formulas for this chapter. thanks

sarah said...

This is a really good and quick summary...I might just print it out for future reference. All these terms and units can get confusing, but here is a way to remember:

Potential difference's symbol is V and it is measured in V (volts)

Current’s symbol is I and the units are ampere – think “I am here”

I know it's stupid...but maybe it will work

Courtney said...

Thanks for the summary it was helpful.

Laura K said...

Nice job summing things up, it made the formulas and everything a lot clearer.