I hope he will get through the exam.
Tip: You may wonder what’s the difference between 彼には, 彼に and 彼は. – All of the three are grammatically correct followed by 試験に受かってほしい, but they have different connotations.
彼は試験に受かってほしい implies that I hope other test takers will fail (because they don’t deserve to pass EXCEPT HIM). Particle は emphasizes the (invisible) two subjects of topic. Its connotation is more negative than the other two phrases.
彼に試験に受かってほしい might suggest that there is only one spot left, and I wish he will get the last spot. Particle に is often used to show a direction of an action (similar to “toward” in English). So, my wish is directed toward him. It’s like a laser beam kind of pinpointing.
彼には試験に受かってほしい is closer to he is the one that I really wish the success in the exam. Unlike the second case 彼に, 彼には doesn’t necessarily mean that there is only one spot left. Particle は in 彼には works the same as the first case 彼は – compare him with other test takers, and pick him up. And, my wish is directed toward him because of particle に. Unlike the first case, there is no negative connotation in 彼には.
So, 彼には試験に受かってほしい suggests that the speaker doesn’t know about other test takers, but the speaker knows that he is a good hard working guy and deserves to pass the exam. And the exam doesn’t have the limit number of acceptance (e.g. passing JLPT level 1).
彼は試験に受かってほしい means that the speaker equally knows all test takers including him, and the speaker wish others to fail in order to give the spot to him.