Answer:FALSE
Explanation: A negative pressure respirator is a respiratory system which is known to have a low air pressure inside the mask when compared to the air pressure on the outside during Inhalation.
Most of the personal protective equipment (PPE) which are in use in various industries are examples of Negative pressure respirator device,any leak or damage done to the device will allow the inflows of harmful and toxic Air into the person's respiratory system. AIR SUPPLY SYSTEMS ARE KNOWN TO SUPPLY FRESH UNCONTAMINATED AIR THROUGH AIR STORED INSIDE COMPRESSED CYLINDERS OR OTHER SOURCES AVAILABLE.
Explanation:
Note: Refer the diagram below
Obtaining data from property tables
State 1:

State 2:

State 3:

State 4:
Throttling process 
(a)
Magnitude of compressor power input


(b)
Refrigerator capacity



(c)
Cop:


Answer:
If everything is working properly, your AC should never need a refrigerant. In fact, a central air conditioner should never need refrigerant added unless there's a refrigerant leak. We'll explain how an AC uses refrigerant and what to do if you think your system is low on refrigerant. OR When you check your air conditioner unit, or your outdoor central air unit with the fan, and see an ice building up on the refrigerant line, then you may be low on freon. ... This will cause the surrounding moisture on the refrigerant line to freeze up. This is a sign you need freon.
Explanation:
(this is according to plumbing services website)
Answer:
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