Whiz quiz is a
slang term for a urinalysis, or a test on urine to determine if the
urine donor has been doing things that he or she should not have been doing.
In the US Navy, for example, I was required to have several per calendar quarter. I had a Secret clearance, and the folks who shall not be named were concerned with the possibility of having us compromised by drug use.
The whiz quiz was one test that you didn't have to study for. If a sailor couldn't urinate on command, it was possible to have a medical officer use a catheter to extract the yellow fluids.