National Grid Flashcards
What are transformers used for
To change voltages and currents in transmission lines
Where are the inputs and outputs on a transformer
Input left output right
What does increasing voltage do
Decreases current
What does decreasing voltage do
Increases current
What does a step up transformer do
- Increases voltage and reduces current
- less current means less energy is lost through heating the wire
Why are transmission lines above ground
To keep people safe from the high voltage wires
What does a step down transformer do
Reduces voltage from transmission voltage to a safer voltage of 230V for home use
How do you ensure minimum amount of power is lost from the cable
- thick cables so resistance is low
- high voltages used to reduce current through transmission lines
How does a low resistance and a low current help transmission wires
- They don’t heat up as much
- less power lost through wires and mostly delivered to consumer
How is energy lost in the power cables
- Due to resistance of the wires
- the bigger the distance between homes and power stations, the greater the loss
Why do step up transformers increase pd
- less ENERGY is lost in the power cables when the pd is very high
Disadvantages of transformers
- very big
- noisy
- don’t look aesthetically pleasing (ugly)
Advantages of transformers
- efficient for high frequency range
- safe
- reliable
