Woody your goals for reading can be as board as you like.
Your purpose is ideally narrowed down so that it points you to your goal. I am not sure that your "ultimate goal" is really to pass the exam since you are sitting for the exams for another reason be it a stage furthering your career... It's worthwhile remembering that (look at the borader picture), because if the sole goal is to sit for exams what difference does it really make if you pass or fail (don't get me wrong I know there is a reason you want to pass and I hope it is a "meaningful" one somewhere along the line).
Now purpose for a book. That is ideally narrowed to a bite sized chunk. So this book is about History. I need to know quite a bit of information in this book. My purpose therefore is to draw out the relevant information ... so that I can... accurately answer the questions to pass on the history test which is a step along the way for my career.
"For the next 30 minutes my goal is to understand the concepts of chapter 3." Ouch my mind never knows when it has understood concepts... likes to keep me going in circles until I can explain to it what a concept is.
Consider the title of chapter 3... Replacing a light bulb. My purpose to know enough about lightbulbs.... so that I can... have light when I read, and I'll know I've achieved this when I can tell someone else how to do it.
For the next 10 minute I am going to activate this chapter to find out how to replace a lightbulb, when I need to replace a lightbulb, why I would need to replace a lightbulb, where does one replace a lightbulb, what I need in order to replace a lightbulb and anything else that is important for me to know when it comes to replacing a lightbulb. Note, I've already developed my superreading and dipping questions because I gained clarity of what my purpose is.
Alex