The'' could only be used if I added ''student'' in the sentence like '' I ranked the first student
This is an important qustion. When should I use "the"?!!
When you say I ranked first, it is like saying I performed best, or I scored highest. You can say I scored the highest, or I performed the best, but the word "the" is awkward here.
So, in this case, get rid of the word the.
However, sometimes modern people -- especially bilingual people, use the in the wrong places. I think it is okay! The world is globalizing, and language is changing faster than ever. Language has always been changing, and now that people of various cultures are coming together, it will change even more. So, keep practicing to learn what sounds awkward, but proceed with confidence, because your way is clear and impressive even if you misuse "the" sometimes. :-)
...my final form six National Exam year 2010, I ranked
the Second Best student second nationally with an average of A.
When you say, "I ranked second," the reader understands that you mean second best.