单选题A direct current passing through a wire coiled around a soft iron core is the description of a simple（）.A magnetic shieldB electromagnetC piezoelectric deviceD electromagnetic domain

题目
单选题
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

相似考题

1.A ship in Hong Kong will sail for Port Said passing through the ________A.Panama CanalB.Grand CanalC.Kiel CanalD.Suez Canal

2.Why did Sturgeon's electromagnet could support nine pounds of iron?A. Because the iron rod was bent into the shape of a “horseshoe”.B. Because the rod was coated with varnish.C. Because a layer of copper wire was wrapped around the rod.D. Because the rod was made magnetic by the passing current.

3.“Stop beating around the bush! If you don’t want to go with me, just tell me!”()A.hitting around the treesB.cheating meC.telling a lieD.avoiding giving me the direct answer

4.Passage TwoQuestions 26 to 30 are based on the following passage.The electromagnet was invented in England by William Sturgeon，who took an iron rod and bent it into the shape of a horseshoe. This “horseshoe” was coated with varnish and a layer of copper wire was wrapped around it. An electric current was passed through the wire，thus making the rod magnetic. The rod was now，because of magnetic attraction，able to support nine pounds of iron. In the US，a scientist named Joseph Henry improved on Sturgeon's electromagnet by insulating the copper wine with silk. He was able to wrap many turns of wire around an iron core without danger of short circuits between the turns. His magnet could hold 2,300 pounds. This experiment prompted Henry to try his hand at converting magnetism into electricity. First he coiled some insulated wire around an iron bar. connecting both ends of the wire to a galvanometer(电流表). The iron bar was placed across the poles of the electromagnet. Then the coil of the electromagnet was connected to a battery. The galvanometer indicated a voltage，then dropped to zero. Henry signaled his assistant to disconnect the coil. The galvanometer showed that once again a voltage had been produced，although this time in the opposite direction. The principle of electromagnetic induction had thus been discovered. Unfortunately for Joseph Henry he did not publish his findings and someone else(Faraday)got the credit for the discovery.The principle of electromagnetic was discovered by______.A. William SturgeonB. Joseph HenryC. FaradayD. someone else

更多“A direct current passing through a wire coiled around a soft”相关问题

  • 第1题：

    Fire dampers prevent the fire spreading through the process of

    A.convection

    B.conduction

    C.radiation

    D.direct contact


    正确答案：A

  • 第2题：

    If kinking results while wire rope is being coiled clockwise, you should______.

    A.coil it counterclockwise

    B.not coil it

    C.take a turn under

    D.twist out the kinks under a strain


    正确答案：C
    当顺时针盘绕钢丝绳时有绞缠，你应转动一下。

  • 第3题：

    The direct way to use XPages in a notes 8.5.1 client is which of the following？（）

    • A、Through a composite application component
    • B、Through use of a file URL
    • C、Client database Launch property
    • D、XPages are accessed through eclipse and not a notes client

    正确答案:C

  • 第4题：

    单选题
    When the current flow through a copper wire increases, its （）
    A

    resistance will decrease

    B

    insulation will bum

    C

    temperature will increase

    D

    conductivity will increase


    正确答案： A
    解析： 暂无解析

  • 第5题：

    单选题
    A DC generator is used to supply direct current in order to maintain an AC generator field and is known as a/an （）
    A

    rotor

    B

    stator

    C

    exciter

    D

    armature


    正确答案： C
    解析： 暂无解析

  • 第6题：

    单选题
    He said current interest rates are a direct_______of domestic(国内的) and international conditions.
    A

    affect

    B

    effect

    C

    income

    D

    outcome


    正确答案： A
    解析：

  • 第7题：

    单选题
    After passing through the turbine the exhaust gas is conducted out into the（）.
    A

    intercooler

    B

    compressor

    C

    cylinder

    D

    open air


    正确答案： C
    解析： 暂无解析

  • 第8题：

    单选题
    For a generator engine, after passing through the turbine the exhaust gas may be conducted out into the （）.
    A

    intercooler

    B

    open air

    C

    oil fired boiler

    D

    B and C


    正确答案： C
    解析： 暂无解析

  • 第9题：

    单选题
    If kinking results while wire rope is being coiled clockwise，you should（）.
    A

    coil it counterclockwise

    B

    not coil it

    C

    take a turn under

    D

    twist out the kinks under a strain


    正确答案： D
    解析： 暂无解析

  • 第10题：

    单选题
    After passing through the expansion valve the refrigerant should be in the state of （）.
    A

    vapor

    B

    liquid

    C

    solid

    D

    None of the above is tree


    正确答案： A
    解析： 暂无解析

  • 第11题：

    单选题
    The cleaned heated oil, after passing through the centrifuges, is to be pumped to a （）.
    A

    settling tank

    B

    service tank

    C

    ballast tank

    D

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    正确答案： A
    解析： 暂无解析

  • 第12题：

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    Which current would you encounter on a direct passage from London，England，to Capetown，South Africa（）.
    A

    Falkland Current

    B

    Brazil Current

    C

    Norway Current

    D

    Benguela Current


    正确答案： B
    解析： 暂无解析

  • 第13题：

    Which of the following components are used to convert alternating current produced in the generator windings to direct current?

    A.Armature and equalizer

    B.Commutator and brushes

    C.Rotor and interpoles

    D.Field and exciter


    正确答案：B

  • 第14题：

    Manila lines in which the strands are right-hand laid ______.

    A.should be coiled in a clockwise direction

    B.should be coiled in a counterclockwise direction

    C.may be coiled either clockwise or counterclockwise

    D.should never be coiled


    正确答案：A
    右旋措拧的马尼拉绳应被顺时针方向盘放。

  • 第15题：

    单选题
    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


    正确答案： B
    解析： 暂无解析

  • 第16题：

    单选题
    A “figure eight” knot is used to（）.
    A

    be a stopper

    B

    shorten a line

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    join lines of equal size

    D

    keep a line from passing through a sheave


    正确答案： A
    解析： 暂无解析

  • 第17题：

    单选题
    In the voyage, duty officer should inform （） situation to the duty engineer immediately.
    A

    in/ut port

    B

    passing through big bridge

    C

    big steering angle for direction changing

    D

    in/out port and passing through big bridge


    正确答案： C
    解析： 暂无解析

  • 第18题：

    单选题
    What is the main reason to slush a wire rope?（）
    A

    Keep the wire soft and manageable

    B

    Lubricate the inner wires and prevent wear

    C

    Prevent kinking

    D

    Prevent rotting


    正确答案： C
    解析： 暂无解析

  • 第19题：

    单选题
    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


    正确答案： D
    解析： 暂无解析

  • 第20题：

    单选题
    The main function of the core of a wire rope is to（）.
    A

    give flexibility

    B

    support the strands laid around it

    C

    allow some circulation around the strands

    D

    allow lubrication inside the rope


    正确答案： C
    解析： 暂无解析

  • 第21题：

    单选题
    Which of the following components are used to convert alternating current produced in the generator windings to direct current?（）
    A

    Armature and equalizer

    B

    Commutator and brushes

    C

    Rotor and interpoles

    D

    Field and exciter


    正确答案： C
    解析： 暂无解析

  • 第22题：

    单选题
    A（）is the intersection of the surface of a sphere and a plane passing through the center of the sphere.
    A

    great circle

    B

    small circle

    C

    large circle

    D

    general circle


    正确答案： A
    解析： 暂无解析

  • 第23题：

    单选题
    When the current in a power transmission line is increased, the power loss （）
    A

    increases as the square of the current

    B

    decreases as the square root of the current

    C

    remains the same, as it is independent of current flow

    D

    increases in direct proportion as the current


    正确答案： D
    解析： 暂无解析

  • 第24题：

    单选题
    Manila lines in which the strands are right-hand laid（）.
    A

    should be coiled in a clockwise direction

    B

    should be coiled in a counterclockwise direction

    C

    may be coiled either clockwise or counterclockwise

    D

    should never be coiled


    正确答案： C
    解析： 暂无解析

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