Why Are You Leaving Your Current Job?

Questions like these are asked to know about your character and temper. If you have a bad experience with your previous company do not express it here. If you start bad-mouthing about your previous company they will misjudge you and will assume that you would do the same when you leave this one. You can use some examples as personal growth stopped, the salary was very less and I was giving much more to the company, reached the end of your learning curve, and so forth.