national grid

• national grid diagram

  
• give on time the demand for energy would be low


  00:00 (not many people using electricity at midnight)
• conventional Power station

  1. The fuel is burned to boil water to make steam
  2. The steam makes a turbine spin
  3. The spinning turbine turns a generator which produces electricity
  4. The electricity goes to the transformers to produce the correct voltage

  conventional Power station diagram with each step labeled

  
• To ensure that the minimum amount of power is lost from the cables:

  • the cables are thick so that their resistance is low
  • high voltages are used to reduce the current through the transmission lines
• what actually is the national grid?

  The National Grid distributes electricity across the country. The National Grid connects power stations to homes, workplaces and public buildings all around the country. The electricity may be produced by a conventional power station turning a generator or by another method.
• what is the use of a step up transformer?


  increases potential difference and decreases current reducing thermal energy transferred to surroundings, increasing the efficiency (of power transmission)
• what is the purpose of a step down transfomer?

  A step-down transformer reduces potential difference to a lower, safer level and therfore increases current. It’s used to make high-potential diffrence electricity from power lines safe for homes and devices. It also ensures that appliances receive the right voltage to work safely and efficiently.
• we know that this is a step down transformer as there is more turns on the primary coil than the secondary.

  
• explain why transformer only work with alternating current (a.c)?


  Transformers work by creating a changing magnetic field, which is only possible with AC. AC constantly changes direction, which causes the magnetic field in the transformer’s core to fluctuate. This changing field induces a current in the secondary coil, allowing the transformer to change (step up or step down) the voltage.
• what is not part of the national grid?

  Power plants and factorys
• what is another name for voltage?


  potential difference
• transformer equation

  
• A worked example using a trick. if the question mark is on the bottom you divide. If the question mark is on the top you multiply.

  
• Explain why no energy transfer is 100% efficient.


  Energy is always lost to the surroundings, often as heat due to friction or other dissipative forces, meaning some energy is not converted into the desired form.