Ohm's law?

Question

I don't really get what ohm's law is. And how do we know if one is ohmic conductor or non-ohmic conductor? Why is light globes non-ohmic conductor?

Answer 1

Ohm's law says that the current is directly proportional to the voltage and oppositely proportional to the resistance, or simply stated: bigger voltage means bigger current, greater resistance means smaller current. Ohmic conductors are those that have constant resistance so that the graph of I vs. Voltage must be a straight line. Light bulbs are thus not perfectly ohmic since R increases as the filament gets hot!

Answer 2

Ohm's law is a statement that in a resistor the voltage is proportional to the current. A non-ohmic conductor like a light bulb has a filament whose resistance varies according to the amount of current flowing through it. Therefore in such a filament, the voltage is not proportional to the current

Answer 3

Ohms Law states that the Current sensity in a circuit is directly propotional to the Electric field. The proportionality constant is arbritray and depends on the nature of the conductor. The conductivity of copper is better that aluminum conductor.The conductivity varies from material to materials.However there is some conductivity in all material. Crystals have some conductivity and are called semiconductors. Conductivity is the inverse of Resistivity. The more the resistivity the less the material will conduct an electric current.
The light Bulbs that you mention contains a tungstan conductor which has a high resistance which increases as temperature increases.That is why it gets hot when an electric current flows thru it,thus it incandesces.

Answer 4

Ohm's regulation hardly ever applies precisely in actual existence, because of fact resistance often relies upon on contemporary. in spite of the undeniable fact that that's totally close for what are called Ohmic conductors. opposite to what some have suggested, the resistance of a superconductor is exactly 0. that's been measured to be below approximately 10^-34 ohms. What this suggests is that a contemporary can circulate devoid of an linked voltage. that's because of fact the voltage represents the flexibility the electrons lose by potential of flowing - and in a superconductor they lose none. It potential which you pick a contemporary source (like a photocell) rather than a voltage source (like a battery or the mains) to get a contemporary to head. commonly, what's carried out with a superconductor is that a vulnerable link is created in the circuit. this might nicely be a sprint bit superconductor that's stored heat, and so would not have 0 resistance. this permits the present source to force a contemporary in the process the superconductor. as quickly as the present is ordinary, the vulnerable link is cooled and the finished circuit superconducts. the present source can then be became off. the present will circulate undiminished continually. Superconducting magnets working like this carry their field indefinitely presented they're stored cool - its how NMR scanners paintings.

Answer 5

Ohm's law: Voltage is in direct proportion to current