| What is Ohms Law? | -Potential Difference [V] = Current [I] x Resistance [Ω] |
| What can I-R Graphs Show you? Show 3 Examples of Some I-R Graphs (Wire & Resistor Graph) (Filament Lamps Graph) ( Diode Graph) | -This can Visualise the Current changes due to the Potential Difference
-1st Example, Wires and Resistors. This is a Linear Graph. The Current is Directly Proportional to the Potential Difference [Temperature has to be Constant] This line can be Steep [Less Resistance] or not [High Resistance] , which comes from the Resistance.
-2nd Example, Filament Lamps. This is a Non-Linear Graph. The Current increases the Temperature , which increases the Resistance, which makes a Curved Diagram.
-3rd Examples, Diode. This is a Non-Linear Graph. Diode will only allow a One Way. If the Lines curves Up at the Positive Side of the Volts, it will be 0 at the Other Side [High Resistance in the Opposite Direction] |
| So how does Temperature Increases Resistance? [Not always the Case] | -When Electrons go through a Resistor, a Bit of its Energy is given to the Thermal Energy Store of that Resistor, which will Heat it Up.
-However Thermal Energy Store is basically the Kinetic Energy Store, so the Heating up of the Resistor also has the Particles Vibrating More.
-This Vibration is a Challenge for our Electrons to get Through, making the Current harder to Flow, and the Resistance Increases
-Some Resistors do have a Limit of the Current that can Flow. Why? More Current = More Thermal Energy = More Resistance = Less Current
-This can Explain the Filament Lamps I-V Graph Levelling off at the High Currents [Or it Broke] |
