physics chapter 6 mcat

current

the movement of charge that occurs between two points and have different electrical potentials

metallic conduction

relies of uniform movement of free electrons in metallic bonds

electrolytic conduction

relies on the ion concentration of a solution

insulators

materials that do not conduct a current

kirchhoff’s laws

express conservation of charge and energy

kirchoff’s junction rule

states that the sum of the currents directed into a point within a circuit equals the sum of the currents directed away from that point

kirchhoffs loop rule

states that in a closed loop the sum of voltage sources is always equal to the sum of voltage drops

resistance

the opposition to the movement of electrons through material

resistors

conductive materials with a moderate amount of resistance that slows down electrons without stopping them

OHM’s law

states that for a given resistance the magnitude of the current through a resistor is proportional to the voltage drop across the resistor

series

resistors in —- are additive and sum together to create total resistance

parallel

resistors in —- cause a decrease in equivalent resistance of a circuit

capacitors

have the ability to store and discharge electrical potential energy

capacitance

in parallel place capacitors is determined by the area of teh plates and the distance between the plates

series

capacitors in —- cause a decrease in the equivalent capacitance of a circuit

parallel

capacitors in —- sum together to create a larger equivalent capacitance

dielectric materials

insulators places between the plates of capacitors that increase capacitance by a factor equal to the materials dielectric constant (k)

Ammeters

inserted in series in a circuit to measure current, they have negligible resistance

voltmeters

inserted in parallel in a circuit to measure circuit drop; they have very large resistance

ohmmeters

inserted around a resistive element to measure resistance they are self powered and have negligible resistance