Published on: Mar 3, 2016
Transcripts - Nationalgrid
Lesson title: National Grid
Class: 10Ph Date: 5th Nov Period: 2 No. Pupils: 30
Lesson Objectives (WALT):
• How the NG is used to transmit electrical energy.
• Why is electricity transmitted at very high & dangerous voltages?
Time Activity Content / Notes (key points, questions to ask, assessment of learning, safety)
Before Have all the equipment where needed.
9.47 Starter 10 Ask students what is written on every pylon and sub-station and why? Explain
mins that the electricity being transferred is very dangerous.
9.57 Main Then explain how so far all we have looked at is producing electricity not
activity 1 getting it to homes afterward. This is done by the national grid, substations
30 mins and powerlines. The idea of the national grid is no area relies on just one
power station they are all connected.
Demo power line a]at 12V
b ] at 240V
Note the differences. Take ideas about why we have mains at 240V (when it
can kill) and transmit at thousands of volts. Power is always the same P=IV so
if V is increased I is decreased. The current controls home much energy is lost
through heat and by resistance so want to keep it low.
Use AQA pg 261 to complete consideration of NG
10.27 Plenary Sheet
Risk Assessment Homework Vocabulary (key words)
13.3 Electricity is transferred from power station to consumers along the NG.
The uses of step-up & step-down transformers in the NG.
Increasing the voltage reduces current, and hence reduces energy losses in cables.
Power line demo, 12V lamp 2, Rubber leads 4, AQA text 20
Sheet The National Grid