Du'a for success in an exam or interview: Be glorified! We have no knowledge

سُبۡحَٰنَكَ لَا عِلۡمَ لَنَآ إِلَّا مَا عَلَّمۡتَنَآۖ إِنَّكَ أَنتَ ٱلۡعَلِيمُ ٱلۡحَكِيمُ

Subhaanaka laa 'ilma lanaa illaa maa 'allamtanaa, innaka Antal 'Aleemul Hakeem

Be glorified! We have no knowledge saving that which Thou hast taught us. Lo! Thou, only Thou, art the Knower, the Wise

Qur'an 2:32 (Al-Baqarah)