P1 - National Grid

Question 1

What are the voltage in the National Grid cables?

Answer 1

400000V

Question 2

Why is the voltage so high in the National Grid cables?

Answer 2

To lower the current

Question 3

Why does the current in the National Grid cables have to be so low?

Answer 3

A high current would mean that most of the energy is lost through heat in the cables

Question 4

How do we increase the voltage of the electricity in the National Grid cables?

Answer 4

We use a step-up transformer that increases the voltage to 400000V and decreases the current

Question 5

How is the voltage of the electricity decreased for use in homes?

Answer 5

A step-down transformer decreases the voltage and increases the current

Question 6

What are the 2 types of National Grid cable?

Answer 6

Overhead cables (with pylons)

Underground cables

Question 7

Give 4 reasons that overhead cables would be chosen instead of underground ones

Answer 7

Low set up cost

Easy to access if there are faults

Easy to set up

Minimal disturbance to land

Question 8

Give 4 reasons that underground cables would be chosen instead of overhead ones

Answer 8

Minimal maintenance needed

Hidden (don’t look ugly)

Not affected by weather

More reliable than overhead cables

Question 9

What are the 2 ways that the increasing demand for electricity could be dealt with?

Answer 9

Energy demands of consumers decrease (could be done by increasing energy efficiency)

Energy supplied to National Grid increased

Question 10

What is the National Grid?

Answer 10

The system over the whole UK that transports electricity from where it’s produced to where it is needed