ziad1985 said:
I'm applying to some a several master program in many Schools, I have to write a letter of motivation, I clearly understand the main concept of it, But what do I have to write in it?
How long should it be?
I know I should be honest, how much honest I have to be?
I have like a hundred question in my head, can some help?
I assume you're applying to master's programs in physics, right?
I wrote my grad school letters mostly for PhD programs (though I did apply to one MS program), but I think the essence of the letter is the same either way.
Here's one idea about what you could write your letter about. I started my statement of purpose with a paragraph on why physics was important to me. I explained why I enjoyed science, and why I majored in physics and math in college. I then wrote a paragraph on what my short and long term career goals were, and how graduate study at the particular institution could help me to achieve those goals. Then I explained briefly some of the research work that I had done as an undergraduate, and why I wanted to do graduate research work. I next explained how I would use my education as a professional scientist (in my case I mentioned my interest in being a physics educator). And finally I wrote a couple sentences saying that the pertinent institution would be the ideal place for me to become a competent physicist.
How long should it be? Mine was a page and a quarter, single spaced. Doesn't mean that yours has to be this length; you should probably check the guidelines that the school you're applying to has specified. Most will specify a limit on the length of your essay.
As for honesty, I think you should be as honest as possible, unless your motivation is to develop some new bomb for the government and make boatloads of cash. I was perfectly truthful in my essay: I just told them that I wanted to go to graduate school so that I could become a physics professor and teach physics, and that got me into grad school. I'd say you should be as honest as possible without saying something that will obviously disqualify you from graduate study. But
don't draw attention to any bad grades or things of that nature. If you were sick one semester and got bad grades, you can typically explain this in an addendum of some sort. Just don't make it part of your essay.
Well, I hope that helps, and good luck!