changes made:
1 added \Omega to symbol Omega
2 reorganize the objects into groups for ease of sharing

Electric cable power loss

Aborb Physics by David Fairhurst free to use on their website only so not embedded here
Transformers and Long-Distance Power Transmission  by Michael Richmond. This work is licensed under Attribution-Noncommercial-Share Alike 2.0 Generic so i am going to share remixed and sharealike so copyright resepcted!