National Grid/ Static electricity Flashcards
What is the national grid?
a giant system of cables and transformers linking power stations to homes and businesses
What do the Power stations in the National Grid do?
throughout the day, electricity usage (demand) changes. Power stations have to produce enough electricity for everyone to have when they need it
They transfer the energy supply into electrical energy
Explain why a smaller number of large power station is more efficient than building many small local power stations.
because large stations can be more efficient.
this is because most power plants use steam turbines which are more efficient at high steam temperatures and the bigger the plant, the bigger the boils, so the higher the steam temperature.
What do step-up transformers do?
transformers that increase the potential difference from the power station to the transmission cables
This reduces the amount of current and therefore also reduces the heating effect caused by current flowing in the transmission cables
Reducing the heating effect …
(how does it affect the transmission)
reduces energy loss so makes the transmission more efficient.
What do transmission cables do?
they transfer the electricity
What do Step down transformers do?
reduce the potential difference from the transmission cables to a much lower value of domestic use
How do you make material electrically charged?
by rubbing two insulating materials against each other
What does the friction between the two insulating material result in? (in terms of electrons)
moves negatively charged electrons from one material to another
Why does charge remain on the object (after rubbing two insulating materials together)
because the materials are insulators
Why can’t charge remain on a conductor?
because they conduct the charge to earth so it cannot build up
What is an isolated object?
an object that has no conducting path to earth
How are electrical sparks formed?
As the charge on an isolated object increases the potential difference between the object and Earth increases
When the potential difference become high enough a spark may jump across the gap, from the object to any earthed conductor near to it
why could electric sparks be dangerous?
because they could serve as a source of ignition
what type of force is an electrostatic force
a non- contact force
