1. How much time is given to an engineer for designing a circuit.
This depends on the complexity of the product, so is really impossible to answer without an example. In most well organized companies the design flow works in cycles, or phases, each cycle including a time of part selection and testing, schematic preparation, circuit board layout, prototype construction and performance testing. Software for the product has a different sequence but its results are also synchronized to this cyclic design flow. Typically the first cycle produces circuits and circuit boards that partially function, that is useful to the software team as a development platform (something to load and test the code in), and that usually doesn't look like or fit into the final product. Second and third phases refine functionality, adjust part choices, tune analog circuits, add functions that were forgotten or misunderstood in previous phases, tweak performance and adjust physical shape/size until it is finally completed. Cycles immediately preceding volume production usually don't change the circuitry very much, but the circuit designer is often assisting the factory in getting test systems running, and troubleshooting yield problems. The number of cycles depends on complexity. For something relatively simple like a thermostat circuit, perhaps one cycle is enough. For something complex, like a cellphone, many cycles are needed. The shortest design job I've ever done lasted only about 2 months to delivery of a sample unit to customer, and in that time, circuit design occupied about 20% of that time. In this very small job, in addition to circuit design, I also had to choose the housing, design the pcb and how it fit into the housing, and do the assembly of the first 25 sample units. To contrast with that job, the most complex design I was involved in actually had a team of roughly six hardware circuit designers, one mechanical designer, roughly twenty-five software engineers, and about six support technicians, not to mention other staff such as production engineer, regulatory engineer, data librarian, pcb layout tech, project manager, field test engineer, test system designer/programmer and a few others. In this larger project, I think that circuit design occupied about 25% of the time, while circuit testing was a larger proportion, perhaps 30%, documentation of your work (reports, specifications, etc) takes another 15% or so, and the remainder was all the other corporate time-using activities like staff meetings, progress meetings, marketing meetings, troubleshooting meetings, general administration (filling out time records etc.), and responding to the avalanche of communications from all the people that can't simply chat with me over the cubicle wall. Needless to say, this avalanche of communications trivia can be irritating and distracting. In the more complex projects, and considering the work is done in cycles, perhaps as many as six cycles, I was often given 6 to 12 months to do my design job for any one product.
2. What do these guys do everyday? By that, I mean do they go everyday and start working like a robot working at conveyer belt.
You come in on time, spend 30 minutes reviewing and responding to emails, then run off to an early project meeting for an hour. Then come back and resume the previous days work of looking for the ideal voltage regulator, or preparing a test specification, or writing code to automate your test sequence on your bench, or laying out a component evaluation pcb or whatever. Mid morning and you decide to stretch your legs, get a coffee in the break room, and wander around to chat with a couple of friends at their cubicles. Then you get back to your desk and resume what you were up to. After a one hour lunch break, you scramble to arrive on time for the 1:00PM group meeting where you fight drowsiness and boredom becuase there are 30 people in the meeting and the subject is of no interest. Escaping that at 2:30, you get back to your desk or bench only to learn from your cubical neighbor that the design specifications have been changed and the design you were working on has to be adjusted to suit. You get over the frustration in about 2 minutes because the challenge of redesign is actually interesting. Another coffee in the afternoon to keep up on your social interaction and to stretch a bit, then a final push to solve one problem before leaving for dinner. Designers work long hours, and the smaller the company, the longer the hours. In the kind of jobs I have had, ranging from junior designer through to mid-level group manager, I've always found the environment to be nothing like an assembly line situation. What I mean is that, for example, at virtually any time you can stop what you are doing, grab a cup of coffee and chat for a few minutes with a friend, and perhaps walk around a bit to get your mind off your work. Designers are usually assumed to be motivated enough that they don't need constant supervision, nobody is hanging over your shoulders and enforcing a certain pace of work minute by minute. Quite a flexible work environment. My bosses started with the assumption that I would act professionally, in the interests of the company and with a mind towards being productive. A good designer meets these expectations, and one that does not does not last very long in a commercial company (ie. one that is in a competitive market, not a government job).
3. How stressful is this job?
Well, again that depends a lot on the kind of company it is. I once worked in a company where virtually none of my design projects made it into volume production. This was actually fun because every few months my project was cancelled and I was given a new assignment, so I had a new challenge and the previous design carried no consequences of sloppy work. Needless to say, that company didn't last too long because my time was wasted by fickle marketing and project goals. In many larger projects, the design innovation, sense of discovery, and glory is in the first half of the project, while the second half is just slogging it out and fiinishing all the stuff that needs to get done for production. If you don't have to do that second part, its actually a lot of fun. So, getting your project cancelled out from under you should not be stressful.
I have worked in a large corporation where your progress is slow and your merit is averaged over many assignments. That job was not particularly stressful. I have also worked in five startup companies, where it is "all or nothing" (go big or go home, succeed or die etc.), everyone is focused on the one product that will make or break the company, and the surety of cash being available to meet payroll was not a given thing. You know what, all of those jobs were highly stressful in some ways, but much more fun. The team is tighter, the goals are usually crystal clear (get the damn thing working!), and the excitement is often palpable in the small startup. To be honest, though, the stress that you feel in your job will be entirely self-generated. If you are prone to nervousness or doubt of your abilities, you will feel a lot of stress. If not, then you will not. its a matter of self confidence.
Some of the stress may be the result of fear over losing your job. The companies will play the gloom and doom card, "meet the deadline or we go bankrupt" or some such version, and you need to understand that this is sometimes simply a ploy to keep you moving along. On the other hand, sometimes it is literally true! Look at it this way, as a designer/engineer you are something of a pawn in a big game. You may be a member in a pool of technical staff that senior management considers as something of a pail of water that they can decant or refill without consequence. By this, I mean that in the technology industry, technical staff layoffs every year or two can be a simple fact of life and should not add to your stress. Layoffs often occur because the company needs to shrink or readjust to cope with changing business fortunes and the reduction in personnel is not a personal attack, in theory (although the question of "who gets kicked out?" is one of "who is the most expendable" which is indeed personal). However, if you have skills, wit and knowledge, you are so highly employable that it just doesn't matter if your company decides to lay you off or not, as you are in demand and can get another job fairly quickly. So, don't sweat it. Consider every job to be temporary and you won't be disappointed. This is not cynicism, just practical advice. As a group or section manager, I've laid off dozens of staff in my career. The ones who understand the big picture respond, when being told the unfortunate news, with a jaunty "ok, well, thanks and I'll look forward to the severance cheque. I wonder what new job I will be doing in a month's time?" and on the other hand, the naive and first-timers sometimes cry. That was a bit stressful for me too.
4. How difficult is the job for a beginner with Master degree but with zero experience? And more importantly what should such a guy do?
If you have managed to do ok at university, then you probably will be able to cope with the difficulty of the job. Common sense dictates that a beginner be given work that he can manage, and be closely watched to see if he copes. The difficulty will be in that you will have to work hard to learn as quickly as possible. You will have to learn how the company works, how the politics work, how the industry does things, how components work, how little they actually taught you in school about the complexities of circuits, how many rules and regulations you must know, where to find parts, where to find information (much easier these days than 30 years ago, although the quality of information tends to be lower now), and why the hell doesn't my circuit work!! What you should do is learn quckly, don't waste your time, pay attention, read everything, listen to the mentors around you, don't kick yourself when you make a mistake or look stupid, and assume that for a few years you will be working 12 hours a day.
I suggest very strongly that you get experience before you get out of school. We have co-operative programs where I live, where the engineering undergrad gets credit for working in industry for four or eight months at a time. People in these programs learn which end of the soldering iron to hold without getting burned, are able to pick up a phone and call a supplier, know how to behave in a staff meeting, don't record overtime in a journal to use as currency, and form the useful link in their minds between what they learn in class and what they apply in the office. Short of this kind of work experience, though, the next best thing is to go out and get any kind of job in a product R&D environment for a company that sells things, even if the job seems lowly. Learn what you can for the sake of experience, and then quit. Yes, you probably will have to leave that company after two years to advance to a more responsible design position. Once you've got a good foothold of a couple of years of experience, it is time to reach for something a bit more responsible and a bit closer to circuit design (if that is your goal). I think that patience is needed in your quest for the ideal job.
5. What's your opinion about a guy who can design layouts using Eagle (but has only theoretical knowledge of EMC), program Atmel microcontrollers (but never did in industry), cannot use Verilog/VHDL, and have never designed any particularly complicated circuit in any industry?
Sounds like a great start. When I am going through a large stack of resumes for a design job, I look for signs that the person is keen on design. I look for signs that this person does electronics as a hobby (ham radio, builds microcontrollers, builds his own test equipment, invents gadgets). I look for basic skills. I also look for evidence that he has studied the theory. So, a degree, diploma or other such academic achievement is mandatory. This guy you refer to seems to have some basic skills and, assuming he has some sort of academic qualifications, I would put his resume in my short pile for an interview to see if I want this guy on my staff as a "fresh-out" (someone who is just fresh out of school). We don't expect a fresh-out to know everything, but we hire the smart ones because they are quick learners.
6. Do they have to sacrifice their social life & work more than 40 hours per week.
Yes, absolutely.