更多"Moisture absorbed in the windings o"的相关试题:
[单项选择]The function of damper windings in a synchronous motor is to （）.
A. eliminate slippage
B. provide excitation
C. provide starting torque
D. increase efficiency
[单项选择]A fire, occurring in the windings, of an overloaded electrical motor, is considered a （）.
A. class "A" fire
B. class "B" fire
C. class "C" fire
D. class "D" fire
[单项选择]Some refrigeration systems have chemical moisture indicators installed in conjunction with the sight glass in the liquid lineIf excess moisture is present in the system, the indicator will （）
A. activate the driers
B. change color
C. secure the compressor
D. add a predetermined amount of liquid drier
[单项选择]Temperature and moisture characteristics are modified in a warm or cold air mass due to （）.
A. pressure changes in the air mass
B. movement of the air mass
C. the heterogeneous nature of the air mass
D. upper level atmospheric changes
[单项选择]A refrigeration system contaminated with moisture can be affected by （）.
A. acid formation
B. sludge formation
C. ice in the expansion valve
D. All of the above
[单项选择]Moisture in the refrigerant may （）.
A. freeze on the expansion valve seat and reduce the flow of liquid refrigerant
B. emulsify the oil in the condenser
C. freeze in the king valve
D. clog the oil trap
[单项选择]The moisture equilibrium chart can be used to determine the（）.
A. Absolute moisture content of the air surrounding a hygroscopic cargo when moisture equilibrium exists
B. Dew point temperature that the air surrounding a hygroscopic commodity will have when in moisture equilibrium with that commodity
C. Enthalpy of the air surrounding a hydroscopic cargo which is in moisture equilibrium with the cargo
D. Temperature at which moisture equilibrium will occur in a cargo hold containing a hygroscopic cargo
[单项选择]The process of removing moisture from air is known as（）.
A. humidification
B. dehumidification
C. vaporization
D. evaporation
[单项选择]In an air conditioning system, moisture is removed from the air by（）
A. filers
B. separators
C. ducted traps
D. dehumidifiers
[单项选择]The ratio of the weight of moisture contained in a given volume of air, to the weight of moisture that the same sample would hold if saturated, is called the（）.
A. absolute humidity
B. relative humidity
C. specific humidity
D. total humidity
[单项选择]Moisture in a refrigeration system can cause （）.
A. freezing the expansion valve closed
B. corrosion of system piping
C. improper temperature regulation
D. all of the above
[单项选择]As the amount of moisture in the air increases, the difference between the dry bulb and wet bulb temperature will （）.
A. increase
B. decrease
C. remain unchanged
D. be greatest at dew point
[单项选择]Moisture in a D-Cmotor would cause （）.
A. short circuit
B. speed up
C. slow down
D. hunting
[单项选择]Increasing the moisture content of conditioned air is known as （）.
A. moisturizing
B. dehumidification
C. dampening
D. humidification
[单项选择]If the moisture content of the cargo sample is（）the Transportable Moisture Limit,then the cargo should be safe to load.
A. above
B. below
C. equal to
D. uncertain
[单项选择]The amount of moisture in a given sample of air, when compared with the amount of moisture the air could hold if totally saturated at the existing temperature of the sample, is called （）.
A. absolute humidity
B. specific humidity
C. effective humidity
D. relative humidity
[单项选择]Moisture is removed from a refrigeration system by（）.
A. bleeding refrigerant from the condenser
B. opening a drain petcock on the oil separator
C. condensing the water in the heat exchanger
D. using a dehydrator cartridge
[单项选择]Moisture should be kept out of an R-12 system because it tends to cause （）.
A. icing of the automatic controls
B. embrittlement of some parts of the automatic controls
C. sludge in the lubricating oil
D. all of the above
