cable used mainly in houses is copper conductors.
the cable sizes are...:
lighting=1mm-1.5mm
sockets-boiler controls=2.5mm
cooker=6mm
shower=10mm (can vary depending on the showers output)
earthing conductor of 10mm
earth bonding conductors of 6mm
25mm tailings (you're supply cables from the meter)
The sizes also depend on weather or not the cable is wired in old colours (i have only entered the new cable sizes)
circuits used are...:
ring main.
radial=only used if there are limited sockets being installed on a circuit.
lighting is just 1 cable going out and spreading to each light and switch (upstairs and downstairs lighting should be on a separate mcb)
cooker-1 cable going out of mcb.
shower-1 cable going out of mcb.
I hope this information helps as i don't fully understand what you are wanting to know from you're question. If you need any more help please let me know, or anyone else for that matter.