Home |
Search |
Today's Posts |
![]() |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
|
LinkBack | Thread Tools | Display Modes |
#25
![]() |
|||
|
|||
![]()
Hi Ratch,
Ratch wrote: Wait a minute, if L&M say that Ohm's law is V=IR (which it is not), and materials that obey Ohm's law are "ohmic", then by L&M's definition, all materials are ohmic because the resistance formula V=IR is always correct for all materials. How is a material defined as "nonohmic"? Ratch No, not quite, ohmic materials by definition have a current density that is *proportional* to the electric field. Or in other words have a rho that is a simple constant. j = E/rho, or E = j * rho If you have a material where rho is not a simple constant, but rather is a function of current density, you have a non-ohmic material. This applies to either way of writing Ohm's law, because rho and R are proportional to each other. So, as a result, if R is some function of I, the material is non ohmic. There is no inconsistency. -Chuck |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
help with power supply | Electronics | |||
POWER SUPPLY NEEDED DC-DC for Auto Hard Drive | Electronics | |||
Power supply repair (Sun) | UK diy |