electricity

• the greater the rate of flow of charge, the greater the current
• the greater the resistance of a component, the smaller the current given for a potential difference across the component
• how does resistance change with current:

  • as current increase, electrons have more energy
  • when electrons flow through resistor, they collide with atoms in resistor
  • this transfers energy to the atoms, causing them to vibrate more
  • this makes it more difficult for electrons to flow through resistor
• how does resistance change with temperature:

  • atoms in resistor have more energy due to temperature increase so they vibrate more
  • makes it more difficult for electrons to flow through resistor
  • (thermistor)- resistance lower in hotter temperatures
• how does resistance change with length:

  • greater the length, the more resistance and lower the current
  • electrons have to make their way through more resistor atoms, so it is harder than using a short wire