An advantage of the air-gap technique is: shorter SID easier ...

[cool]

An advantage of the air-gap technique is:
 
 shorter SID
  easier positioning
  greater efficiency
  eliminates the use of a grid

Question 2

If mAs were to increase, what would be the effect?
 
 decreased penetration
  increased penetration
  increased density
  decreased density

[samiel-sayed]

Answer to Question 1

eliminates the use of a grid

Rationale: The air-gap technique can be a substitute for use of a grid. The increased OID allows the scatter to deflect in pathways from the image receptor, therefore increasing the contrast.

Answer to Question 2

increased density

Rationale: Milliamperage-seconds, mAs, contributes to the overall blackness of the image. It represents the quantity of radiation produced.