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OAT Physics
Chapter 8 - DC and AC Circuits
Term | Definition |
---|---|
conductors | materials that allow electric charge to freely move within the material; metals |
insulators | materials where electric charge aint free to move, retard flow of electricity; nonmetals |
Current | opposite electron flow; charge/time = Ampere |
V = | emf - IR |
Ohm's Law | V = IR |
As length of wire/temp increases | resistance increases |
As cross sectional area increases | resistance decreases |
R = | ro L/A |
P = | IV = V^2/R = I^2R |
Currents in DC | same current for all resistors; amount in = amount out |
Resisters in series | add up so Rtot = R1 + R2 etc; everything gets the same current and V adds up |
Parallel | 1/Rtot= 1/R1 + 1/R2 etc; everything gets the same V and I adds up |
capacitor | a two plate system that stores charge |
capacitance C | = Q/V; total = 0 cuz +Q and -Q; Farad units; = e0 A/d |
e0 | 8.85E-12 |
Dielectrics | insulators that increase capacitance when inserted btwn plates of a charged capacitor; does so by decreasing voltage |
C' | =KC |
Capacitor in parallel | add up |
Capacitor in series | 1/Ctot = 1/C1 + 1/C2 etc |
rms current/voltage | = Imax/square root of 2 ; Vmax/square root of 2 |