Prayer text does not always have to be prescribed by someone else. G‑d understands your language too. An appropriate prayer before a major exam would be something along the lines of, “G‑d, please help me pass this exam.” Perhaps you could elaborate on that and explain to G‑d why it means so much to you, or why it’s important for you to do well. It’s always good to get into the habit of praying to G‑d in a manner of talking to Him. You’ll begin to feel that you have a working relationship with Him, and you’re not just always reading a pre-prepared script at set times.
If you’d feel more comfortable having a standard prayer to go along with that, my suggestion would be Chapter 121 in Psalms. The theme of the psalm is the general assistance G‑d provides us, and our success being dependent on Him. It’s short and convenient. I’ve said it on a number of different occasions when I felt in need of some Divine assistance.
Wishing you lots of luck on your test,
Malkie Janowski for Chabad.org
Prayer for Preparation to Study
Lord, I know you are with me and love me.
Give me peace of mind as I prepare for this time of study.
Help me to focus on my books and notes,
keep me from all distractions so that I will make the best use
of this time that is available to me.
Give me insight that I might understand what I am studying ,
and help me to remember it when the time comes.
Above all, I thank you for the ability to be able to study
and for the many gifts and talents you have given me.
Help me always to use them in such a way
that they honour you and do justice to myself. Amen
Prayer Before an Examination
Dear Lord, as I take this exam, I thank you that my value
Is not based on my performance, but on your great love for me.
Come into my heart so that we can walk through this time together.
Help me, not only with this test, but the many tests of life that are sure to come my way.
As I take this exam, bring back to my mind everything I studied
and be gracious with what I have overlooked.
Help me to remain focussed and calm, confident in the facts and in my ability,
and firm in the knowledge that no matter what happens today you are there with me. Amen