Dr. Abner Mallity's graduate students are trying to confuse him.  They claim that they have devised a system or circuit that has the Nyquist plot below.  Mallilty says it can't be - that it is impossible to have a Nyquist plot that intersects like this one.

Help Mallity out.  Answer the following questions to the best of your ability.

• Is this Nyquist plot possible?  (i.e., is there a system that could produce a Nyquist plot like this one?)
• If this is a Nyquist plot for a real system, what can you determine about the system from the Nyquist plot?