Electronics engineering and Mechanical engineering are interconnected to each other?

Well, for one thing, current technological trends are embedding electronics in a lot of machines, and most electronic devices have some sort of mechanical interface to allow them to transfer data and general information to and from the user. In my own case, through the years, I've been fascinated by how many devices have replaced almost all the "logic" originally provided by mechanical contrivances with electronics, specifically digital electronics. There was a time (yes, when dinosaurs roamed the earth :-) ) when a kid could actually take a machine apart, figure out how it worked by simply looking at it and watching it work, and fix it and learn from it independently. Not so any more. Yes, electronics and mechanics are inextricably linked and getting more so every day. Even in the early days of integration, much of the logic of a mechanical device and of an electronic device mirrored each other. And many analogies for explaining electronics can be constructed with mechanical models. Another thing to be aware of is that if you limit your thinking and learning to a narrow set of studies and fields, you'll often find yourself missing alternative implementations and some real opportunities for elegant solutions. Plus, I personally find the overlap between fields to be eye-opening.

Absolutely. There was a time when they were not so intrinsically married to each other and many mechanical devises were just that -- purely mechanical. As time went on, more and more "mechanical logic" contrivances have been replaced with electronics -- usually digital electronics. Just look at a modern automobile and see how many devices that were formerly mechanical only have been replaced with computers and other solid-state control mechanisms. They're smaller, cheaper, more reliable and more flexible. Another thing to consider is the fact that knowledge of both those fields will not only keep you more up-to-date with current device technologies, but also give you a lot more flexibility in devising solutions to problems. Combining the two gives you much more latitude and the potential for elegant -- and efficient -- solutions and products. And I've found that knowing either makes it easier to understand the other. Plus, it's more fun.

Yes, Modern control systems are eletronic and run computer programs, which control the mechanical systems.