Electricity and the National Grid

Question 1

What does the national grid do?

Answer 1

Takes electrical energy from power stations to where it’s needed in homes and industry.

Question 2

What is the problem with a high current?

Answer 2

Loads of energy is lost through heat in the cables.

Question 3

Describe the role of step-up and step-down transformers in the national grid.

Answer 3

Step-up transformers are used to boost the voltage up really high at one end and then step-down transformers bring the voltage back down to safe, usable levels at the other end.

Question 4

What is an advantage and disadvantage of using overhead cables in the national grid?

Answer 4

Advantages: cheapest to set up, easy to access, easy to set-up, minimal disturbance to land
Disadvantages: High maintenance, ugly, affected by weather, sometimes unreliable.

Question 5

What is an advantage and disadvantage of using underground cables in the national grid?

Answer 5

Advantages: minimal maintenance, hidden, not affected by weather, generally reliable
Disadvantages: Higher set-up cost, hard to access, hard to set-up and lots of disturbance to land.

Question 6

How can demand by consumers be reduced?

Answer 6

Consumers could use more energy efficient appliances.

Question 7

How can supply be increased?

Answer 7

Opening more power plants.