I'm not dismissing them off the bat, just trying to inject some realism. These positions are the most competitive ones due to the huge numbers that apply to them - they're the first stop for virtually all engineering graduates seeking engineering work after graduation, in my experience. And...
In my experience technical tests have never been of the level where an actual calculator and formula handbook has been needed. Not to say that they don't exist, though.
In my experience technical interviews involve actual technical content, like how stuff works, equations and how you'd go about performing a technical task. I'm sorry if that sounds a bit obvious, but I suppose it's in contrast to an HR interview where the questions are typically like "tell me...
Have you looked into accountancy/finance? Software development? Both of which are popular destinations for physics graduates. I think that, unless you want a job that really needs a specific masters, there isn't really any point in doing one as it'll cost you money and delay your entering into...
People are willing to pay more money for social media stuff than they are for electronics (except for their phones). Hence, more money available in making social media apps.
Generally speaking the higher up the ladder you go the further you go away from the technical aspects of engineering, but it's not always like this. Some smaller, specialised design/consultancy type firms will have a higher ratio of technical people to management types than your average...