4) Network theory: – 

Network analysis techniques:-
https://www.youtube.com/watch?v=QYE6uZlPqZY

Network theorems:-
https://www.youtube.com/watch?v=bnjiLg4xfh8&list=PLmJ90L1wsHRnHf01eyqH0CvIvq0J-Om_f

steady state sinusoidal response:-https://www.youtube.com/watch?v=Gwy2HjLn8Ko

Two port networks:-https://www.youtube.com/watch?v=GasWAlIvvD8&list=PL16EE39765482C57F

Network graphs and their applications in network analysis:-
https://www.youtube.com/watch?v=F8qiM3o0Jc0

Z, Y, h and transmission parameters:-
https://www.youtube.com/watch?v=WVxWesqPto8

Analysis of common two ports:-
https://www.youtube.com/watch?v=OebCfH9T3r8

Combination of two ports:-
https://www.youtube.com/watch?v=iIjMzXmILXk

Network functions : obtaining a network function from a given part:-https://www.youtube.com/watch?v=b8rYb_kt5Ng

parts of network functions:-
https://www.youtube.com/watch?v=kI5So5YSRvI

Elements of network synthesis:-
https://www.youtube.com/watch?v=SpTbySxrQWI

Transmission criteria : Elmore’s and other definitions effect of cascading:-https://www.youtube.com/watch?v=t57TSl2IDu0

Transmission criteria :delay and rise time:-
https://www.youtube.com/watch?v=XP8l832K0Aw

standard book:-

• Hayt engineering circuit analysis 8th edition:-http://www.slideshare.net/louizrae/hayt-engineering-circuit-analysis-8th-txtbk
• Edminister-ElectricCircuits sham series:-https://archive.org/details/TheoryAndProblemsOfElectricCircuits