electricity

IG物理 第二单元课程整理，包含1.电路中的电流和电压、抵抗、 电荷、市电等。希望此脑图对你有所帮助！

electricity

• 1.current and voltage in the circuits
  • conductor, insulation and electric current
    • voltage
    • current
    • 形成原因：delocalised electron moving at same direction
    • ohm law :
  • measuring current
    • ammmeter
      • ammeter is in series with component in the circuit
    • charge（库仑）单位
    • current : the size of current mean the rate of the charge pass through the circuit
      • Q = I * t charge current time
  • voltage
    • how much energy is transffered from each charge in the circuit
      • E = Q * V energy charge voltage
    • measuring voltage
      • voltmetter
  • Component
  • series and paralla
    • series
      • only one path
        • the switch can control ever component
        • 电流与电压的变化规律
          • the current that passes through the ever component is same
          • the sum of voltage of component is equal to the cell or battery
    • paralla
      • more than one path
        • the switch can only control component in the same path
        • 电流与电压的变化规律
          • the voltage that pass though the each path is equal to the cell (or battery)
          • the sum of current that pass through the each path is equal to the main current
• resistance
  • ohm law :
  • 测量电阻
    • • gradient=1/R
  • 各种用电器电阻
    • resistor
    • lamp
    • diode
    • thermistor
    • light-dependent resistor
  • variable resistor
    • control the amount of current pass through the circuit
• electric charge
  • 原子结构
    • postive charge : proton
    • uncharge: neutron
    • negative charge: electron
  • 电荷移动产生正电荷与负电荷的数量不同，使得物体带电
    • rub : 使电荷转移
    • 如何验证
    • opposite charge attract . similiar charge repeal
      • 实验验证
• mains electricity
  • line structure
    • • live wire: energy transfer through this wire
      • neutral wire: complete the circuit
      • earth wire: protect you if there is a fault
  • safe
    • fuse
      • 规格
        • 3A
        • 5A
        • 13A
      • 原理：If too much current pass through the fuse, the fuse will be melted, the circuit will not be complete
    • double insulation
      • 原理
    • swith
      • complete with live wire
      • reasons
  • 生热原因
    • 1.high resistance 2.electron collide with atom 3.theelectric energy thransfer to the thermal energy andlight energy
  • 交流电与直流电
    • 直流电
      • the same direction of current and voltage
    • 交流电
      • the different direction of current and voltage
• 电荷不会凭空产生或消失
• 在这里 charge 不再是电荷的意思 而是库仑