The transmission cables of the National Grid are made of aluminium because it has low resistance. The cables are thick to reduce power losses in heating.
P1 The National Grid
1. National Grid: See Summary.
2. Voltage from power station is increased using step up transformer.
This is done to reduce current so not much heat is lost from cables.
The voltage is then reduced to 230 V using step down transformer.
The voltage on the National Grid is a.c not d.c .
1. National Grid: See