# G482 Electricity

• G482 Electricity
• Current
• Change in Charge= Current x change in time.
• Q=I x t
• Coulomb is unit of charge and is amount of charge that passes in 1 second when the current is 1 ampere.
• Current is the rate of flow of charge.
• Drift velocity
• Average velocity of electrons
• I = nAvq
• Current depends on drift velocity
• Current
• Change in Charge= Current x change in time.
• Q=I x t
• Coulomb is unit of charge and is amount of charge that passes in 1 second when the current is 1 ampere.
• Current is the rate of flow of charge.
• P.d. or Voltage
• The energy converted per unit charge moved.
• The energy per unit of charge.
• P.d. or Voltage
• The energy converted per unit charge moved.
• The energy per unit of charge.
• V= W/Q
• The p.d across a component of 1 volt when you convert 1 joule of energy moving 1 coulomb of charge.
• V= W/Q
• The p.d across a component of 1 volt when you convert 1 joule of energy moving 1 coulomb of charge.
• Resistance
• R=V/I and is measured in ohms.
• 3 things determine resistance- Length, Area and Resistivity
• Resisitivity: p=RA/L and R=p x 1/A
• In ohmic conductors, R is constant as long as temperature is constant.