An air-conditioning unit is located on the roof of a commercial building. the dis-
connecting means for the equipment is:
a. permitted to be a switch capable of being locked in the open position and located
not in sight of the equipment.
b. required to be located within sight of the equipment and readily accessible from
the equipment.
c. required to be capable of being locked in the open position even when located
within sight of the equipment.
d. not permitted to be attached to the outside of the air-conditioning equipment.
e. not permitted to be installed within the air-conditioner enclosure.
code reference

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Inspection for bearing condition will include: (clo4) a)-color b)-smell c)-size d)-none of the above