The way I grade core graduate courses

The core courses in the graduate curriculum of the Physics Department are 
instrumental in covering the basic breadth requirements for Ph.D. work in the
department. The Ph.D. qualifying exam is traditionally given after these core 
courses are taken by the students, and is a go/no-go threshold for Ph.D. studies
in all reputable universities. The usual time for this exam is at the start of 
the Ph.D. studies. This timing is crucial to maintain the quality of the 
Ph.D. program.

A number of factors have forced the department to move the qualifying to a 
time after all Ph.D. courses have been taken, when appreciable time and 
resources have been spent by the department and the student during the program.
The exam therefore has now been structured differently, and is no longer a 
check of the breadth requirement for Ph.D. studies.

For this reason, the grades obtained from the core graduate courses are now a 
very important indicator of the level of achievement, and serve as a 
requirement for progress in (if not admission to) the Ph.D. program. I 
therefore construct exams which are not quite at the level of difficulty of a 
qualifying exam question, but nevertheless require a solid understanding of 
the subject. A "barely sufficient level of achievement for Ph.D." level 
(say 80%) in the course will correspond to a B letter-grade. A Ph.D. track 
student who has obtained a lower grade will need to repeat the course until 
(s)he achieves a sufficient level of achievement. A student who has performed 
at a minimum satisfactory level will receive a C letter-grade, which may be 
compensated by an A letter-grade to maintain the 2.5 GPA requirement for the 
M.S. program. Lesser/higher level achievements will correspond to lower/higher