网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
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
参考答案
参考解析
解析：
暂无解析
更多 “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” 相关考题
考题
A ship in Hong Kong will sail for Port Said passing through the ________A.Panama CanalB.Grand CanalC.Kiel CanalD.Suez Canal
考题
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
考题
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.
考题
“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
考题
Fire dampers prevent the fire spreading through the process ofA.convectionB.conductionC.radiationD.direct contact
考题
Which of the following components are used to convert alternating current produced in the generator windings to direct current?A.Armature and equalizerB.Commutator and brushesC.Rotor and interpolesD.Field and exciter
考题
If kinking results while wire rope is being coiled clockwise, you should______.A.coil it counterclockwiseB.not coil itC.take a turn underD.twist out the kinks under a strain
考题
Manila lines in which the strands are right-hand laid ______.A.should be coiled in a clockwise directionB.should be coiled in a counterclockwise directionC.may be coiled either clockwise or counterclockwiseD.should never be coiled
考题
The direct way to use XPages in a notes 8.5.1 client is which of the following？（）A、Through a composite application componentB、Through use of a file URLC、Client database Launch propertyD、XPages are accessed through eclipse and not a notes client
考题
单选题A direct current passing through a wire coiled around a soft iron core is the description of a simple（）.A
magnetic shieldB
electromagnetC
piezoelectric deviceD
electromagnetic domain
考题
单选题When the current flow through a copper wire increases, its （）A
resistance will decreaseB
insulation will bumC
temperature will increaseD
conductivity will increase
考题
单选题A “figure eight” knot is used to（）.A
be a stopperB
shorten a lineC
join lines of equal sizeD
keep a line from passing through a sheave
考题
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
rotorB
statorC
exciterD
armature
考题
单选题In the voyage, duty officer should inform （） situation to the duty engineer immediately.A
in/ut portB
passing through big bridgeC
big steering angle for direction changingD
in/out port and passing through big bridge
考题
单选题He said current interest rates are a direct_______of domestic(国内的) and international conditions.A
affectB
effectC
incomeD
outcome
考题
单选题What is the main reason to slush a wire rope?（）A
Keep the wire soft and manageableB
Lubricate the inner wires and prevent wearC
Prevent kinkingD
Prevent rotting
考题
单选题After passing through the turbine the exhaust gas is conducted out into the（）.A
intercoolerB
compressorC
cylinderD
open air
考题
单选题Inductance is the property of an electric circuit that （）A
opposes any change in the applied voltageB
opposes any change in the current flow through the circuitC
aids any changes in the applied voltageD
aids any changes in the current through the circuit
考题
单选题For a generator engine, after passing through the turbine the exhaust gas may be conducted out into the （）.A
intercoolerB
open airC
oil fired boilerD
B and C
考题
单选题The main function of the core of a wire rope is to（）.A
give flexibilityB
support the strands laid around itC
allow some circulation around the strandsD
allow lubrication inside the rope
考题
单选题If kinking results while wire rope is being coiled clockwise，you should（）.A
coil it counterclockwiseB
not coil itC
take a turn underD
twist out the kinks under a strain
考题
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 equalizerB
Commutator and brushesC
Rotor and interpolesD
Field and exciter
考题
单选题After passing through the expansion valve the refrigerant should be in the state of （）.A
vaporB
liquidC
solidD
None of the above is tree
考题
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 circleB
small circleC
large circleD
general circle
考题
单选题The cleaned heated oil, after passing through the centrifuges, is to be pumped to a （）.A
settling tankB
service tankC
ballast tankD
drain tank
考题
单选题When the current in a power transmission line is increased, the power loss （）A
increases as the square of the currentB
decreases as the square root of the currentC
remains the same, as it is independent of current flowD
increases in direct proportion as the current
考题
单选题Which current would you encounter on a direct passage from London，England，to Capetown，South Africa（）.A
Falkland CurrentB
Brazil CurrentC
Norway CurrentD
Benguela Current
考题
单选题Manila lines in which the strands are right-hand laid（）.A
should be coiled in a clockwise directionB
should be coiled in a counterclockwise directionC
may be coiled either clockwise or counterclockwiseD
should never be coiled
热门标签
最新试卷
