I took this class during the pandemic. It was definitely hard focusing but Prof Jiang is really sweet and I think he genuinely cares for his students. I really hated the method of the midterm because if you miss an answer, your work doesn't count and you lose the point. But I took the option final which boosted my grade. In conclusion, I will definitely recommend professor Jiang.

DISCLAIMER: I took this class during Spring '20, which was the corona quarter.

Prof Jiang was not engaging at all, I found myself skipping lecture then going back and watching it on 2x speed. As for the material, I think 5A was definitely harder than 5C, and 5C was harder than 5B, but Jiang did a relatively good job explaining things. It was interesting for me, and I have like no care for electricity and stuff.
Originally he said he was going to grade on a curve, so watch out for that. Since we took our midterms on MasteringPhysics however, he ended up grading on a straight scale so that even if people cheated, there would be an equal chance for everyone to get an A. With the midterms being online, it was all-or-nothing, meaning if you got a question wrong out of the 4-question midterm, you'd be at a C. It was open note however, so I think people did well. The final ended up being optional due to (justified) nationwide outrage, but for those who chose to take it, you had the chance of earning partial credit, and it was similar to the practice final he posted a week before. I will say this, Jiang was sweet and accommodating, and always looked for student input before making decisions. I'd take a class with him again, only if it were bruincasted though haha.