Is it appropriate for a professor to give the same exam to two different classes 2 weeks apart?
I deduce that one section is taught in French and another section is taught in English? The tests should be given in the language that the class is taught in. However, if there is reason to believe that all students are fluent in one language (e.g. English), it is debatable whether the language of the exam is actually of consequence. 

Does your university require all students to be competent in English (or in French)? I guess it could be argued that students who only speak English should not be required to take a test in French. 

Seeing as this is an engineering course, it would seem that there would not be a significant advantage to students who attend the French section versus the English section.