All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
You must fast during the month of Ramadan and breaking the fast due to the examination is forbidden. Exams or the like activities are not an Islamicly valid excuse to give up the fasting in Ramadan even if the student faces hardship. Such a hardship does not justify breaking the fast during Ramadan since it is bearable. A student should bear in his mind that obedience of Allaah is the most important means to get blessings and success in this life and the next life while disobedience is the greatest means for failure and disappointment.
Allaah Knows best.