更多"When the current flow through a cop"的相关试题:
[单项选择]A direct current passing through a wire coiled around a soft iron core is the description of a simple（）.
A. magnetic shield
B. electromagnet
C. piezoelectric device
D. electromagnetic domain
[单项选择]When cutting wire rope，seizings are put on each side of the cut.The seizings prevent the wire from unlaying and also（）.
A. Maintain the original balance of the tension in the wires and strands
B. Prevent moisture from entering between the wires at the cut end
C. Forces lubricant from the core to protect the raw，cut end
D. All of the above
[单项选择]A rotary current sets through all directions of the compass. The time it takes to complete one of these cycles is approximately（）.
A. 3 hours
B. 6 1/2 hours
C. 12 1/2 hours
D. 25 hours
[单项选择]When working with lumber, wire and staples are not desirable to be used because（）.
A. they are not subjected to cause trouble
B. they are difficult to handle this kind of cargo
C. the efficiency of separating is raised
D. the efficiency of loading is greater
[单项选择]When measuring AC current flow, you must always connect the meter （）
A. in series with the power source and load
B. in parallel with the power source and load
C. insuring correct polarity
D. using the lowest range possible to prevent instrument damage
[单项选择]When a deck cargo is secured with chain or wire lashings and grab (pear) links，which statement is FALSE?（）
A. The amount of take-up is limited by the length of the turnbuckle
B. At the grab (pear) link，the slack end of chain should be led back and secured to the chain above the link
C. The lashings should be inspected each day and any slack taken up
D. The turnbuckle should be secured with a stick or lock nuts
[单项选择]When the power is shut off, the wire（）
A. becomes slack
B. can not be paid out unless the brake is overhauled or recover wire unless manually operated
C. will be let out because the brake is out of work
D. may be pay out due to no power
[单项选择]When referring to dry bulk cargoes，the term “flow state”（）.
A. designates the state of a commodity when the ship is heeled past the angle of repose
B. relates to the suitability of loading a cargo by flowing down inclined chutes
C. refers to the saturation of a dry bulk product with water to the point where it acts as a liquid
D. relates to the minimum granule size of a particular product where it will flow like a liquid at an angle of 30°
[单项选择]When securing a hook to the end of a wire rope you should use（）.
A. A bowline knot
B. A long splice
C. An overhand knot with a wire rope clip
D. Wire rope clips with a thimble eye
[单项选择]For a vessel with transverse inclination，an increase in GMT causes（）.
A. list to stabilize at an angle of loll
B. list to decrease
C. trim to decrease
D. list to increase
[单项选择]For a ship with longitudinal inclination，an increase in GML causes（）.
A. list to stabilize at an angle of loll
B. trim to stabilize at an angle of loll
C. trim to increase
D. trim to decrease
[单项选择]Compensated flow control or constant flow valves are used in hydraulic systems to（）
A. compensate for major leaks in the system
B. maintain the original fluid viscosity
C. allow for changes in pressure and temperature within the system
D. assure constant fluid temperature
[单项选择]Most conducting materials such as copper, aluminum, iron, nickel, and tungsten （）.
A. increase in resistance with increased temperature
B. increase in resistance with decreased temperature
C. decrease in resistance with increased temperature
D. increase in conductance with increased temperature
[单项选择]The world's supplies of copper（）
A. have gradually being exhausted
B. are gradually exhausted
C. has been gradually exhausted
D. are being gradually exhausted
[单项选择]Copper is often used as an electrical conductor because it （）.
A. has high resistance at low temperatures
B. has a highly polished surface
C. is able to pass current with little opposition
D. holds insulation together well
[单项选择]low flow sensor位于（）
A. 主电子设备舱
B. 驾驶舱
C. 前电子设备舱
D. 空调舱
