Topic 3.2 Resistance and Resistivity Flashcards
Name 3 Physical factors than could affect the resistance of a wire
Cross Sectional Area, Length, Resistivity
How does increasing the length of a conductor affect its resistance?
Increases
How does increasing the CSA affect resistance?
Larger CSA = Lower Resistance
Define resistivity
A property that determines its resistance to current flow
What does a higher resistivity do?
Increases resistance
Equation for factors that affect resistance of conductor
R = pL/A
How does the potential along a wire vary as you move along it?
Potential increases
What is the terminal potential difference of a supply?
The actual potential difference that is produced across the terminals
Define internal resistance
Internal resistance of a power supply is the electrical resistance with the materials of the supply
What is a semiconductor
A component that can change its resistance based on external conditions (e.g LDR)
Describe how resistance of a thermistor changes with decreasing temperature
Resistance increase
Describe how the resistance of a LDR changes as light intensity increases.
Resistance decreases
What is a potential divider
A pair of resistors that split pd
