In TV and movies with time travel as a plot, Nazis or some other group will get a cell phone, or computer from the present, and it completely changes the time line. Would it have been possible for scientists in the 1940's to learn any useful information from modern electronics?
Also not sure which subreddit to place this. I had thought /r/askscience , but this is probably more of a history question.
I would say it's better in askscience because while the scientists in the past could easily understand the functional blocks of modern highly integrated electronics (I'm thinking circuitry) they would not have the equipment necessary to investigate it, especially digital stuff in part due to the speeds involved.
If it had a surface mount transistor yes. Say you have a phone, it's got a digital processor, but it also has an ideal mixer ic and a tiny transistor amp.
In this case they might look at the three pins on the transistor and realize it works like a tiny vacuum tube.
The construction would be simple enough to replicate.