How many motor designs does NEMA designate?

How many motor designs does NEMA designate?
 
  a. 2
  b. 5
  c. 7
  d. 10

 Q. 2

In refrigeration and air conditioning, switches are normally wired:
 
  A) In either series or parallel with the load they control.
  B) In series with the load they control.
  C) In parallel with the load they control.
  D) In parallel with the power supply.

 Q. 3

Undersized suction lines:
 
  A) Can cause poor oil return because of high refrigerant velocity.
  B) Can reduce system efficiency because of a high pressure drop.
  C) Can reduce system efficiency because of a low pressure drop.
  D) Can cause poor oil return because of low refrigerant velocity.