更多"（） is used to produce electric powe"的相关试题:
[单项选择]What type of electric motor is most commonly used on board ship?（）
A. non-synchronous electric motor
B. synchronous electric motor
C. fully enclosed electric motor
D. watertight electric motor
[单项选择]Freon 12 which is used to produce intense cold is normally a （） when at atmospheric pressure and temperature.
A. liquid
B. gas
C. solid
D. water only
[单项选择]If an electric cargo winch is being used to lift a draft of cargo and the engine room loses all power，which will occur?（）
A. A pawl，forced by a spring mechanism，will engage the teeth of the bull gear and hold the load
B. An electromagnetic brake will hold the load where it is suspended
C. The load will fall rapidly to the deck unless the foot brake is engaged
D. The load will slowly lower to the deck under control of the drag of the winch motor
[单项选择]（）are used to digest the sewage to produce innocuous sludge in a biological sewage treatment plant.
A. anaerobic bacteria
B. aerobic bacteria
C. air bubbles
D. disinfection chemicals
[单项选择]Radar beacons are transmitters designed to produce a（）on the screens of ship’s radar sets.
A. incorrect image
B. distinctive image
C. pictorial image
D. pictographic image
[单项选择]Cumulonimbus clouds can produce（）.
A. dense fog and high humidity
B. gusty winds，thunder，rain or hail，and lightning
C. clear skies with the approach of a cold front
D. a rapid drop in barometric pressure followed by darkness
[单项选择]Electric circuits are protected against overloads and short circuits by means of a/an （）.
A. circuit breaker
B. amplifier
C. diode
D. capacitor
[单项选择]Why will a turbocharger diesel engine produce black smoke if excessive additional load is applied too quickly?（）
A. Exhaust energy would draw excess air
B. The inertia of the turbocharger rotor causes a time lag which delays the turbocharger speed increase
C. Exhaust gas pumping losses are increased due to turbine windage
D. Exhaust gas back pressure falls slightly due to increased nozzle action
[单项选择]Electric generators can be protected against overload（）.
A. With switches
B. With a governor on the engine
C. With fuses or circuit breakers
D. By using heavy wire
[单项选择]Electric insulation is made of organic substances and so gradually （） with age.
A. deteriorates
B. increases
C. are fouled
D. becomes better
[单项选择]Diesel engine electric starting motors generally require heavier duty motors and motors and operate at higher voltages than comparable starting motors for gasoline engines due to（）
A. higher speed required
B. flywheel-effect
C. lower starting temperatures
D. higher compression pressures
[单项选择]Which of the listed problems could produce a high absolute pressure within a flash type evaporator?（）
A. Production of high salinity distillate
B. Seawater feed temperature below 165℃
C. A leak in the first stage demister
D. A cracked distillate pump vent line
[单项选择]Electric cargo winches have an overload safety device which normally cuts the current to the winch motor（）.
A. after torque cause line pull to exceed the rated capacity of the winch
B. before the line pull reaches the rated capacity of the winch
C. when the line pull reaches the breaking strengh of the fall
D. before the safe working load of the fall is reached
[单项选择]Overspeed of the diesel engine driving an electric generator could cause（）.
A. low voltage trip
B. reverse power trip
C. damage to windings
D. excessive exhaust temperatures
[单项选择]Capacitance is the property of an electric circuit opposing a change in the （）
A. current in the circuit
B. voltage in the circuit
C. inductance in the circuit
D. resistance in the circuit
[单项选择]Inductance is the property of an electric circuit that （）
A. opposes any change in the applied voltage
B. opposes any change in the current flow through the circuit
C. aids any changes in the applied voltage
D. aids any changes in the current through the circuit
[单项选择]An electric heater built into some smaller diesel engines is used to （）.
A. raise lube oil viscosity for easier starting in cold weather
B. increase air inlet temperature
C. increase compression ratio
D. increase jacket water temperature for easier starting in cold weather
