Is studying the wrong material for an exam, despite one's commitment to acts of worship, considered a tribulation from Allah?

Trial is a test and a purification, aimed at atoning for sins, effacing misdeeds, elevating ranks, and increasing good deeds, as happened with the Prophets. It also serves to purify believers and distinguish them from hypocrites, or it may be a punishment for a believer for some sins. A believer must be patient in trial to attain the reward of the patient.