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GCSE Level Questions: Transformers

Q4. The diagram shows how electricity is distributed from power stations to consumers.

(a)

(i) Which parts of the diagram above form the National Grid?

Tick one box.

  Tick here
power station, transformers and power cables  
transformers and power cables
transformers, power cables and consumer  

[1 mark]

(ii) The power cables shown are 'overhead power cables'. Power cables can be buried underground.

Give one disadvantage of burying power cables underground.

Any one from:

(more) difficult to repair / replace

(more) expensive to install / repair

(more) difficult to identify a break

potential hazard if dug up

Damage to (animal) habitats was ignored...

[1 mark]

(b) Complete each sentence below by choosing a word from the box below. Each word can be used once or not at all.

energy
efficiency
power
voltage
current

 

The step-up transformer increases the voltage which decreases the current . Using a step-up transformer increases the efficiency of the electricity distribution process.

[3 marks]

(c) A householder reads his electricity meter at the start and at the end of a month.

Start:
34 523 (kWh)
End:
34 713 (kWh)


If the cost of 1 kWh is 15 pence, calculate the cost of the electricity used that month.

34 713 - 34 523 = 190 units

190 x 15p = 2850p = £28-50

[2 marks]

(7 Marks Total)