Supplying Electricity Efficiently

Question 1

What makes having a high current not very efficient?

Answer 1

High current makes cables get hot, which means some energy is wasted as heat energy.

Question 2

What is voltage increased to before it is sent round the country?

Answer 2

400,000 V.

Question 3

What does increasing the voltage lower?

Answer 3

Current.

Question 4

What do you need before you increase voltage?

Answer 4

A step-up transformer.

Question 5

To bring voltage down to safe usable level what is needed?

Answer 5

A step-down transformer.

Question 6

Transformers can only be used on which type of current? AC or DC?

Answer 6

AC.

Question 7

Finish the equation: total energy input=

Answer 7

Useful energy output+ waste energy output.

Question 8

What is the equation for working out efficiency percentage?

Answer 8

Efficiency= (useful energy output/total energy input) x100

Question 9

To transmit a lot of electrical power what are the two things you need either of?

Answer 9

High voltage or a high current.