Are they going to test my accounting skills by any exams in interview or after?

Is there any sample exams to have an idea about its difficulty?

if you are going into the consulting/advisory side there is a test that you would have to take that is similar to whatever they take at a consulting firm like accenture.  if you are just talking about tax or audit, there is no sort of exam.  you interview would be simply talking about your experience and questions like "Tell me about a time when...".