The job interviews are conducted to see how much a candidate is qualified to perform that job. The job interviews are laid down in different formats. They follow different formats keeping in mind the convenience of both the employer and the job candidates.
An interview follows a set of procedures. The procedure of any interview is that the interviewer (employer) asks questions to the interviewee (candidate). The employer asks the job candidate different questions as per the requirements. If the job candidate answers his questions well, then he will qualify for a job. A job interview should be more of a one way communication. The employer should have more speaking right than the employee. The candidate should not ask anything during the interview. It is against the pattern of the interview. When the employer finishes his job then he asks you to put forward your questions. This is your turn to speak now.
You should never say 'I don't have any questions' instead make the best use of the opportunity and put forward your queries. This is a good chance for you to get the company information and details which the employer has not disclosed to you. Be smart while you ask. Your questions should not directly indicate what you are intending to know. Raise your questions based on the questions that were put to you by the employer.
Other than this you can ask questions that should not cross your limit of rights. You can ask your expected pay if you were not asked during the interview by the employer, ask about the leave holidays, paid vacations, bonuses, working hours, training and development programs of the company etc.