V = IR & I-V graphs

• Graph for filament lamp

  
• Symbol for a diode

  
• What does a diode do

  Only allows current to flow one way around a circuit
• Graph for a diode

  
• How does temperature affect resistance

  Increasing the temperature will increase the resistance
• Graph for a fixed resistor

  
• Why does increasing the temperature of a wire increase its resistance

  Higher temperatures make particles in the wire vibrate faster which impedes (slows) the flow of electrons, increasing the resistance