Electrodynamics

Electrodynamics Electrodynamics -CORRECT ANSWER- The study of electric charges in motion. A charge flow when there is a potential difference across the ends of a conductor Potential difference -CORRECT ANSWER- The force/ strenght of electron flow. Tot. maxx difference of potential between positive and negative ends. The greater the excess of electrons (negative charge) at one pt. and deficiency of electrons (positive charge) at another, the greater the attraction or POTENTIAL vetween points. Potential diff Unit of measurement -CORRECT ANSWER- Volt Voltage definition -CORRECT ANSWER- sometimes abbreviated "E" (electromotive force). 1joule(J) of work done on 1 coulomb of charge. (1volt=1joule/1coulomb) Current -CORRECT ANSWER- The flow of electron charge. Intensiy of electric current determined by number of elecrons flowing past in one second. Ampere -CORRECT ANSWER- current unit of measurement/ movement of 6.24 x 10^18 electrons per second. 1 coulomb of electrical charge flowing per second. (1amp=1coulomb/second) Direct current (DC) -CORRECT ANSWER- Electrons flow in the same direction through a conductor. from point a to point b. Continuous DC -CORRECT ANSWER- An even/uniform current. A battery makes direct current; e-move from repelling (-)terminal and toward attracting (+) terminal, always moving thorugh circuit in same direction Pulsating DC -CORRECT ANSWER- moves in surges Alternating current (AC) -CORRECT ANSWER- E- move first in one direction and then reverse and move in other direction through a conductor.>causes change in both amplitude and direction of current.>> accomplished by alternating direction @ energy source. Resistance definition -CORRECT ANSWER- amount of opposition to the flow of electrons in an electric current. Resistance -CORRECT ANSWER- dependent on type of material. >a materials atomic structure determines its conductivity.>>Outer electrons of metal atoms are loosely bound and can be earily detached to move through material. Electrons in rubber, ceramics -CORRECT ANSWER- very tightly bound.;it is very difficult for an electric charge to move through these materials Copper -CORRECT ANSWER- used more exclusively in electric wiring than any toher metal as it offers less resistanc to flow of electric current than any other common material Length of material -CORRECT ANSWER- Resistance of a conductor is directly proportional to its lenght (longer the wire, greater the resistance) Thickness of material -CORRECT ANSWER- Resistance of a conductor is inversely proportional to cross-sectional area (the thicker the wire, the less resistance) Temperature -CORRECT ANSWER- For most conductors, increased temp is accompanied by increased.(exception is Carbon) Carbon -CORRECT ANSWER- Exception to temp. carbon resistance decreases w/increased temperature which will increase electric current. Ohm -CORRECT ANSWER- un