Socratica is a YouTube channel chalk-full of high-quality videos on a variety of subjects with a focus on math, science, and arts and humanities. Clicking on the Playlists tab will show the variety of subtopics available on the channel, 25 in total, ranging from Astronomy and Biology to Algebra and Geometric Constructions to even a Glossary of Art terms and Shakespeare Sonnets.
The number of videos in each playlist varies as does the length of individual videos. For the longer videos that you might want to use only a portion of, check out my post on how to clip the beginning AND end points of a YouTube video.
Ever since I started using the quiz feature in Google Forms to conduct assessments I have been on the lookout for high-quality videos like these. I will insert them into the “Add feedback” panel of a Form question so that students can use them to help “brush up” on the material and as a study tool if a re-assessment is needed.