PHYS 212 Lecture 8: 2/20/17
Document Summary
Change potential difference increasing v increases current. Current will be much higher through metal than through wood. Current will decrease the longer it must move. Combine all of these into one property: resistance the cross-section area. = where is the resistivity of material, l is the length, and a is the unit is ohm =1(cid:1848)/1 resistivity, measured in ohm meters . All objects of the same material and temperature have the same temperature is a measure of kinetic energy of atomic particles. As electrons move through wire they hit ions ions vibrate in place, increasing kinetic energy, which increases temperature. Why wires heat up resistance increases with heat this is the basis for incandescent light bulbs. 0is a reference resistivity at temperature t0. Is a temperature coefficient of the material. Vbatt = vwire this is true for an arbitrary number of wires. Resistance is defined by a relationship between potential and current.
