Unit 5, Resistance Flashcards
Potential Difference
The amount of energy transferred from electrical energy to other forms of energy per unit charge flowing between two points
Do electrons flow in the same direction as the current
No, they flow in the opposite direction to the current
The electrons in a current collide with the positive ions in the wire, causing … . This process is called electrical …
Kinetic energy to be lost and the temperature of the wire to increase.
Resistance
Power
The energy transferred per second
The equation for resistance
R = V/I
What is the gradient of a V-I graph
Resistance
What are the four factors that affect resistance in a wire
Temperature
Length
Cross-sectional area
Material
Resistivity
Equivalent to the resistance in 1m of a wire of a certain material with cross-sectional area of 1m^2 at a specific temperature
how does the resistance of a wire varies with temperature
Linearly
Why does temperature effect resistance as it does
Because an increase in temperature increase the vibrational energy of the ions in the wire. this causes the electrons to collide more frequently
What is a superconductor
a metal that has 0 resistance at very low temperatures,
What is the temperature a called when a metal becomes a superconductor
The transition temperature, normally close to absolute 0
