The IITs have taken up an initiative of starting online teaching and thus have started offering course materials online for every engineering stream.Many professors from all the IITs have provided course materials for each chapter and each subject.
One has to register at the link provided below and can access the course material free of cost.
Every Chapter has been described with diagrams and charts. Please spread this message to everyone, as many can benefit from this program taken up by the government and IIT.
This is just a trial period going on and hence i request everyone to register at the link given.