on表示在考试中，in表示在一场考试上。in the exam比on the exam具体。exam，主要用作名词，用作名词译为“考试；测验”。例句：What about your exam？你的考试情况如何？

in the exam例句

These kinds of questions often appear in the exam.

这几类问题在考试中经常出现。

In the exam there's sure to be a question on energy.

考试时准有关于能量的题目。

Credit will be given in the exam for good spelling and grammar.

考试中拼写和语法出色者将受到表扬。

on the exam例句

He confessed to cheating on the exam.

他承认自己考试作弊。

Build yourself up to peak performance on the day of the exam.

好好准备在考试那天发挥出最高水平。

A lot of people got a perfect score on the exam.

这次考试很多人都拿了满分。