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下列关于磁场的叙述，其中不正确的是（） The following statement about magnetic field is incorrect （)
A.在磁铁周围放入小磁针，磁铁产生磁场，取走小磁针，磁铁周围的磁场就消失了Put a small magnetic needle around the magnet. The magnet generates a magnetic field. Take away the small magnetic needle, and the magnetic field around the magnet disappears#B.某一点磁场方向，就是放在该点的小磁针静止时北极所指的方向The direction of the magnetic field at a certain point is the direction of the north pole when the small magnetic needle placed at that point#C.磁感线是有方向的，在磁体周围的磁感线都是从磁体的北极出来，回到南极The magnetic li参考答案和解析
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更多 “下列关于磁场的叙述，其中不正确的是（） The following statement about magnetic field is incorrect （)A.在磁铁周围放入小磁针，磁铁产生磁场，取走小磁针，磁铁周围的磁场就消失了Put a small magnetic needle around the magnet. The magnet generates a magnetic field. Take away the small magnetic needle, and the magnetic field around the magnet disappears#B.某一点磁场方向，就是放在该点的小磁针静止时北极所指的方向The direction of the magnetic field at a certain point is the direction of the north pole when the small magnetic needle placed at that point#C.磁感线是有方向的，在磁体周围的磁感线都是从磁体的北极出来，回到南极The magnetic li” 相关考题
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About the following IP addresses , Which is incorrect ?A．201.199.255.11B．201.198.132.1C．201.199.128.6D．201.198.134.257
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In the following statements about functional dependency, which one is incorrect?A．If X→Y and Y→Z, then X→Z.B．If X→Y and, then X→Y'.C．If X→Y and, then X'→Y.D．If, then X→X'.
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Which one of the followings is incorrect about magnetic compass?______.A.The magentic compass is compulsory on my vesselB.The magentic compass is prone to errorC.The magentic compass is always placed inside steel constructionsD.The magentic compass needs to be calibrated to compensate for local magnetic distortion
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A pilot chart does NOT contain information about ______.A.average wind conditionsB.tidal currentsC.magnetic variationD.average limits of field ice
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Permanent magnetism is caused by ______.A.operation of electrical equipment and generators on board shipB.the earth's magnetic field affecting the ship's hard iron during constructionC.the horizontal component of the earth's magnetic field acting on the horizontal soft ironD.the vertical component of the earth's magnetic field acting on the vertical soft iron
考题
Which statement about the gyrocompass is FALSE ________．A.Its accuracy remains the same at all latitudesB.It seeks the true meridianC.It can be used near the Earth's magnetic polesD.If an error exists，it is the same on all headings
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If a magnetic compass is not affected by any magnetic field other than the Earth’s which statement is TRUE?______.A.Compass error and variation are equalB.Compass north will be true northC.Variation will equal deviationD.There will be no compass error
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共用题干
第一篇The Northern LightsThe sun is stormy and has its own kind of weather.It is so hot and active that even the Sun's gravity cannot hold its atmosphere in check!Energy flows away from the Sun toward the Earth in a stream of electrified particles that move at speeds around a million miles per hour.These particles are called plasma （等离子体）,and the stream of plasma coming from the Sun is called the solar wind.The more active the Sun,the stronger the solar wind.The solar wind constantly streams toward the Earth,but don't worry because a protective magnetic field surrounds our planet.The same magnetic field that makes your compass point north also steers the particles from the Sun to the north and south poles.The charged particles become trapped in magnetic belts around the Earth.When a large blast of solar wind crashes into the Earth's magnetic field,the magnetic field first gets squeezed and then the magnetic field lines break and reconnect.The breaking and reconnecting of the magnetic field lines can cause atomic particles called electrons trapped in the belts to fall into tile Earth's atmosphere at the poles.As the electrons fall to the Earth,they collide with gas molecules in the atmosphere,creating flashes of light in the sky.Each atmospheric gas glows a different color.Oxygen and nitrogen glows red and green arid nitrogen glows violet purple.As these various colors glow and dance in the night sky,they create the Northern Lights and the Southern Lights.Watching auroras（北极光）is fun and exciting, but normally you can only see them in places far north like Alaska and Canada.The movement of the aurora across the sky is usually slow enough to easily follow with your eyes but they can also pulsate（跳动）,flicker（闪烁）,or even move like waves.During solar maximum,5 auroras are seen as far south as Florida,even Mexico!Auroras often seem to be very close to the ground,but the lowest aurora is still about 100 kilometers above the ground,a distance much higher than clouds are formed or airplanes can fly.A typical aurora band can be thousands of kilometers long,a few hundred kilometers high,but only a few hundred meters thick.We hope you are able to travel to far north places like the Arctic Circle and see the Northern Lights at least once during your lifetime.We know you will never forget it!What happens when solar wind comes to the Earth?A:It is trapped in magnetic belts around the Earth.B:A protective magnetic field is formed at the same time.C:It destroys the protective magnetic field surrounding the Earth.D:It breaks magnetic field lines and does severe damage to the Earth.
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共用题干
The Northern LightsThe Sun is stormy（狂暴的）and has its own kind of weather. It is so hot and active that even the Sun ' s gravity cannot hold its atmosphere in check（控制，支配）!Energy flows away from the Sun toward the Earth in a stream of electrified particles（电粒子）that move at speeds around a million miles per hour. These path- dles are called plasma（等离子体）, and the stream of plasma coming from the Sun is called the solar wind. The more active the Sun,the stronger the solar wind.The solar wind constantly streams toward the Earth,but don't worry because a protective magnetic field （磁场）surrounds our planet. The same magnetic field that makes your compass point north also steer（引导）the particles from the Sun to the north and south poles.The charged particles become trapped in magnetic belts around the Earth.When a large blast of solar wind crashes into the Earth's magnetic field,the magnetic field first gets squeezed and then the magnetic field lines break and reconnect.The breaking and reconnecting of the magnetic field lines can cause atomic particles（原子粒子）called electrons（电子）trapped in the belts to fall into the Earth ' s atmosphere at the poles. As the electrons fall to the Earth,they collide with gas molecules（分子）in the atmosphere,creating flashes of light in the sky. Each atmospheric gas glows a different color. Oxygen and nitrogen glow red and green and nitrogen glows violet- purple. As these various colors glow and dance in the night sky,they create the Northern Lights and the Southern Lights.Watching auroras is fun and exciting,but normally you can only see them in places far north like Alaska and Canada. The movement of the aurora across the sky is usually slow enough to easily follow with your eyes but they can also pulsate（跳动）,flicker,or even move like waves. During solar maximum,auroras are seen as far south as Florida,even Mexico!Auroras often seem to be very close to the ground,but the lowest aurora is still about 100 kilometers above the ground,a distance much higher than clouds are formed or airplanes can fly.A typical aurora band can be thousands of kilometers long,a few hundred kilometers high,but only a few hundred meters thick.We hope you are able to travel to far-north places like the Arctic Circle and see the Northern Lights at least once during your lifetime.We know you will never forget it!The Earth is quite safe with a magnetic field surrounding it to protect it from the attack by the solar wind.A:RightB:WrongC:Not mentioned
考题
共用题干
The Northern LightsThe Sun is stormy（狂暴的）and has its own kind of weather. It is so hot and active that even the Sun ' s gravity cannot hold its atmosphere in check（控制，支配）!Energy flows away from the Sun toward the Earth in a stream of electrified particles（电粒子）that move at speeds around a million miles per hour. These path- dles are called plasma（等离子体）, and the stream of plasma coming from the Sun is called the solar wind. The more active the Sun,the stronger the solar wind.The solar wind constantly streams toward the Earth,but don't worry because a protective magnetic field （磁场）surrounds our planet. The same magnetic field that makes your compass point north also steer（引导）the particles from the Sun to the north and south poles.The charged particles become trapped in magnetic belts around the Earth.When a large blast of solar wind crashes into the Earth's magnetic field,the magnetic field first gets squeezed and then the magnetic field lines break and reconnect.The breaking and reconnecting of the magnetic field lines can cause atomic particles（原子粒子）called electrons（电子）trapped in the belts to fall into the Earth ' s atmosphere at the poles. As the electrons fall to the Earth,they collide with gas molecules（分子）in the atmosphere,creating flashes of light in the sky. Each atmospheric gas glows a different color. Oxygen and nitrogen glow red and green and nitrogen glows violet- purple. As these various colors glow and dance in the night sky,they create the Northern Lights and the Southern Lights.Watching auroras is fun and exciting,but normally you can only see them in places far north like Alaska and Canada. The movement of the aurora across the sky is usually slow enough to easily follow with your eyes but they can also pulsate（跳动）,flicker,or even move like waves. During solar maximum,auroras are seen as far south as Florida,even Mexico!Auroras often seem to be very close to the ground,but the lowest aurora is still about 100 kilometers above the ground,a distance much higher than clouds are formed or airplanes can fly.A typical aurora band can be thousands of kilometers long,a few hundred kilometers high,but only a few hundred meters thick.We hope you are able to travel to far-north places like the Arctic Circle and see the Northern Lights at least once during your lifetime.We know you will never forget it!Some scientists are worrying about the possible disappearance of the Earth's protective magnetic field in the future.A:RightB:WrongC:Not mentioned
考题
Which of the following is true about the MPLS header and its EXP field size？（）A、The MPLS header is 2 bytes，and the EXP field is 3 bits long.B、The MPLS header is 1 byte，and the EXP field is 3 bits long.C、The MPLS header is 4 bytes，and the EXP field is 3 bits long.D、The MPLS header is 3 bytes，and the EXP field is 3 bits long.
考题
Identify the INCORRECT statement about the Configurations and Options Guide （COG）： （）A、IBM Marketing Option part numbers， Feature Codes and Field Replacement Unit part numbers are listedB、DS3000 and DS4000 storage products are includedC、Console switches and related KVM options are described in a separate chapterD、UPS information is provided
考题
when eduar tried open the coming attractions view. he got the following error message: incorrect data type for operator or @function: text expected. What did he do to cause this to happen?（）A、entered text in a number fieldB、neglected to place a formula in a validation eventC、neglected to place a formula in a translation eventD、combined a text field and a time field in formula
考题
Which of the following statement is incorrect regarding RMAN？（）A、It detects corrupt blocks.B、It performs only offline database backups.C、It omits empty blocks during backups.D、It performs tablespace point-in-time recovery （TSPITR）.
考题
单选题Which statement about the Flinders bar of the magnetic compass is CORRECT（）.A
It compensates for the error caused by the vertical component of the Earth's magnetic fieldB
It compensates for error caused by the heeling of a vesselC
It compensates for quadrantal deviationD
It is only needed in equatorial waters
考题
单选题If a magnetic compass is not affected by any magnetic field other than the Earth’s，which statement is TRUE? （）A
Compass error and variation are equalB
Compass north will be true northC
Variation will equal deviationD
There will be no compass error
考题
单选题Which statement about the gyrocompass is FALSE（）.A
Its accuracy remains the same at all latitudesB
It seeks the true meridianC
It can be used near the Earth's magnetic polesD
If an error exists，it is the same on all headings
考题
单选题The coil of wire rotating in the magnetic field produces the（）.A
voltageB
currentC
powerD
frequency
考题
单选题To increase the frequency of an operating AC generator, you should （）A
increase the field excitationB
decrease the field excitationC
increase the number of magnetic polesD
increase the speed of the prime mover
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单选题During the transition of the Earth’s magnetic field _____.A
the compass will become uselessB
man and animals will be confused as to directionsC
the magnetic strength of the Earth will disappearD
the magnetic strength of the Earth will be stronger
考题
单选题When placed in a magnetic field, which of the materials listed will maintain the highest permeability?（）A
GlassB
BakeliteC
Soft ironD
Aluminum
考题
单选题According to the passage, _____.A
we should not worry about the transition of the Earth’s magnetic fieldB
the Earth’s magnetic field will not change for at least 2000 yearsC
the Earth’s magnetic field has decreased its strength rapidlyD
the transition of the Earth’s magnetic field can be controlled by modern science
考题
单选题Which of the following is true about the MPLS header and its EXP field size？（）A
The MPLS header is 2 bytes，and the EXP field is 3 bits long.B
The MPLS header is 1 byte，and the EXP field is 3 bits long.C
The MPLS header is 4 bytes，and the EXP field is 3 bits long.D
The MPLS header is 3 bytes，and the EXP field is 3 bits long.
考题
单选题Which of the following statement is incorrect regarding RMAN？（）A
It detects corrupt blocks.B
It performs only offline database backups.C
It omits empty blocks during backups.D
It performs tablespace point-in-time recovery （TSPITR）.
考题
单选题Permanent magnetism is caused by（）.A
operation of electrical equipment and generators on board shipB
the earth's magnetic field affecting the ship's hard iron during constructionC
the horizontal component of the earth's magnetic field acting on the horizontal soft ironD
the vertical component of the earth's magnetic field acting on the vertical soft iron
考题
单选题A ship under construction or major repair will acquire permanent magnetism due to（）while sitting stationary in the earth’s magnetic field.A
hammering and jarringB
vibration and poundingC
varying magnetic fieldsD
stable or permanent magnetism of the ship
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