There is no single "exam dua" in the hadith, but the Quran and Sunnah have duas for knowledge, a clear mind and ease that suit studying and tests perfectly.
قَالَ رَبِّ ٱشْرَحْ لِى صَدْرِى وَيَسِّرْ لِىٓ أَمْرِى وَٱحْلُلْ عُقْدَةًۭ مِّن لِّسَانِى يَفْقَهُوا۟ قَوْلِى
Rabbish-raḥ lī ṣadrī, wa yassir lī amrī, waḥlul ʿuqdatam-min lisānī, yafqahū qawlī
My Lord, open my chest for me, make my task easy for me, and untie the knot from my tongue, so they understand my speech. (The dua of Musa)
Quran 20:25-28
فَتَعَٰلَى ٱللَّهُ ٱلْمَلِكُ ٱلْحَقُّ ۗ وَلَا تَعْجَلْ بِٱلْقُرْءَانِ مِن قَبْلِ أَن يُقْضَىٰٓ إِلَيْكَ وَحْيُهُۥ ۖ وَقُل رَّبِّ زِدْنِى عِلْمًۭا
Rabbi zidnī ʿilmā
My Lord, increase me in knowledge.
Quran 20:114
اللَّهُمَّ لَا سَهْلَ إِلَّا مَا جَعَلْتَهُ سَهْلًا، وَأَنْتَ تَجْعَلُ الْحَزْنَ إِذَا شِئْتَ سَهْلًا
Allāhumma lā sahla illā mā jaʿaltahū sahlā, wa anta tajʿalul-ḥazna idhā shiʾta sahlā
O Allah, nothing is easy except what You make easy, and You make the difficult easy if You will.
Sahih Ibn Hibban 974, graded sahih
Our teachers will check the Arabic and transliteration on this page before launch.
Guide
There is no single "exam dua" in the hadith, but the Quran and Sunnah have duas for knowledge, a clear mind and ease that suit studying and tests perfectly.
Study well, then say these before revising and before the exam starts. Pray two rakahs and ask Allah in your own words too. Effort and dua go together.
Questions
Rabbish-rah li sadri wa yassir li amri (Quran 20:25-28), and Allahumma la sahla illa ma jaaltahu sahla (Ibn Hibban 974).
Yes. Personal dua can be made in any language. Use these Arabic duas as well if you can.