Elicit, surely?
But seriously, I adjust my style depending on the class, but I tend to run quite relaxed classes (in some ways) so that people don't feel quite so unwilling to contribute. That tends to help things, as well as letting people answer what they can, and able to say that they don't know something. Of course, the flip side is that I expect people to have done at least a minimum of work in advance.
Edited to add, Supras, the expression you're looking for is "Scotch cringe".