move in an opening direction
move in a closing direction
either open or close
not move at all
第1题:
When the prime movers of two paralleled generators are equipped with mechanical-hydraulic governors, and are operating within their designed range, the unit with the least amount of speed droop will .
A.pick up more of any increase in load
B.pick up less of any increase in load
C.share an equal amount of any increase in load
D.drop an equal amount of any decrease in load
第2题:
An increase in the heat load to a refrigeration system will cause ______.
A.the suction pressure to decrease
B.the suction temperature to increase
C.increased ice formation on the evaporator coil
D.excessive short cycling of the compressor
第3题:
If the compensating needle valve of a hydraulic governor is opened more than necessary the governor will .
A.have a larger than normal dead band
B.produce excessive speed response to a load change
C.respond slowly to any change in engine load
D.stabilize engine speed at the new governor setting
第4题:
be jammed
be opened
be seated
be broken
第5题:
have a larger than normal dead band
produce excessive speed response to a load change
respond slowly to any change in engine load
stabilize engine speed at the new governor setting
第6题:
The temperature of the refrigerant in the evaporator coil depends mostly upon the ___.
A.refrigerant pressure in the evaporator
B.cooling water temperature to the condenser
C.heat load in the refrigerator compartment
D.solenoid valve in the liquid line
第7题:
第8题:
When replacing a thermostatic expansion valve sensing bulb, it is necessary to
A.apply a light film of oil to increase heat transfer
B.apply a light film of oil to prevent oxidation
C.apply a heavy coating of grease to function as a heat sink
D.carefully coat the device with silicone sealant to reduce the effects of convective cooling
第9题:
maximum power at a normal load
maximum power and load under normal conditions
half speed and normal temperature
normal operating temperature without a load
第10题:
the inlet valve is open
the exhaust valve is open
both valves are close
both valves are open