PHYSICS- P2

• in a series circuit potential difference is shared
• in a series circuit current is equal throughout the circuit
• V=IR (Voltage= Current x Resistance)
• Resistance is shared depending on the current and potential difference (total resistance add the resitances together)
• in Parallel circuit the potential difference is the same everywhere
• in a parallel circuit the current shared between all the branches but the first ammeter is the sum of the other ammeters
• the resistance in a parallel circuit is calculated by the equation V=IR for each branch (the total resistance is lower than the lowest resistance
• lowest gradient highest resistance on an IV graph
• constant gradient= constant resistance in an IV graph
• ohmic conductor graph- constant resistance in both directions
• filament lamp graph- resistance increases at high voltages as the bulb gets warmer
• diode graph- current only passes in one direction as there is high resistance in the flat side
• national grid- system of cables and transformers that carry electricity across UK
• Vp x Ip = Vs x Is ( primary voltage x primary current = secondary voltage x secondary current)
• green and yellow earth wire = 0V
• brown wire live wire 230V and 50 Hz
• Blue wire neutral wire 0V
• Resistance is low current increases, fuse blows stopping the current flowing into the live wire, the earth wire stops the wire from being live