Electrical Energy and Domestic Electric Circuits (Leaving Cert Physics): Flashcards
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15 cards from this deck
Power loss formula in transmission lines
Power loss formula in transmission lines
(current squared × resistance)
Why high voltage transmission reduces power loss
Why high voltage transmission reduces power loss
Higher V → lower I for same P; loss ∝
Mains voltage in Ireland/EU
Mains voltage in Ireland/EU
230V AC
Live wire voltage range
Live wire voltage range
+325V to -325V (RMS 230V)
Neutral wire voltage
Neutral wire voltage
Zero volts (Earth potential)
Purpose of earthing in electrical systems
Purpose of earthing in electrical systems
Connects metal parts to Earth; prevents electrocution
Earth wire colour
Earth wire colour
Green/yellow striped
Required position for fuse connection
Required position for fuse connection
In the live wire
RCD function
RCD function
Detects live/neutral current difference; prevents electrocution
RCD disconnection time
RCD disconnection time
Less than 30 milliseconds
Definition of kilowatt-hour (kWh)
Definition of kilowatt-hour (kWh)
Energy used by 1000W appliance in 1 hour
1 kWh in joules
1 kWh in joules
J
Energy calculation formula
Energy calculation formula
Current calculation from power and voltage
Current calculation from power and voltage
I = rac{P}{V}
MCB advantage over traditional fuse
MCB advantage over traditional fuse
Faster operation; resettable (no replacement needed)