I've tried to think why you want to do this, and came up with the following:
- Students work on assessments only during specific times when they are in the lab. Solution: You can set access times on any quiz, or you can use the Course Schedules plugin, https://moodle.org/plugins/block_horario, to restrict access times for the entire course.
- You want to know who is seated by whom in order to check for cheating. Solution: Reduce the chances of cheating by create quizzes in which answers are shuffled each time, question order is shuffled each time, or questions are drawn from a random set of questions in a question bank.
- You want an easy way to take attendance: Solution: Use the Moodle Attendance plugins, https://moodle.org/plugins/?q=attendance, https://moodle.org/plugins/block_attendance, or set specific times for the quiz, as in #1 above.
Floyd