Bubbles are seen in the sight glass of an R-12 system. Technician A says this that indicates a fully charged system. Technician B says that it indicates an empty system, the bubbles being caused by vapor left in the system. Who is correct?

Technician B says that it indicates an empty system, the bubbles being caused by vapor left in the system.

Explanation:

Bubbles mean that the R-12 system is low in charge or an empty system, and the bubbles being caused by the vapor which is left in the system. The bubbles are the indication of low charge or an empty system. And hence, here Technician B seems to be the correct person, and hence the correct choice here is Technician B.

you are welcome for my answer it is b⇔⇒⊕