Well, I've got an MS and I know what is what.
My favorite question is to ask about the equals() method in Java. Why would you need to override it, and what *else* might you need to do...
If they don't get that they're almost certain to get the boot immediately.
I once had a guy who wrote on his resume "expert at Java 1.4.x API". So I asked him to tell me a little about what interfaces and classes were in the java.util package. "uh, I don't memorize the packages, I use Javadocs to look stuff up". OK, how about the collections framework. Tell me about some of the classes and interfaces there. Surely, you can come up with something you don't have to look up. "UHhhh...".