高考物理知识点总结磁场电磁感应

高考物理知识点总结——磁场、电磁感应高考物理知识点总结——磁场、电磁感应1.现将电池组、滑线变阻器、带铁芯的线圈A、线圈B、电流计及开关如下图连接，在开关闭合、线圈A放在线圈B中的情况下，某同学发现当他将滑线变阻器的滑动端P向左加速滑动时，电流计指针和右偏转。由此可以判断BA.线圈A向上移动或滑动变阻器滑动端P向右加速滑动，都能引起电流计指针向左偏转B.线圈A中铁芯和上拔出或断开开关，都能引起电流计指针向右偏转C.滑动变阻器的滑动端P匀速向左或匀速向右滑动，都能使电流计指针静止在中央D.因为线圈A、线圈B的绕线方向未知，故无法判断电流计指针偏转的方向2(如图，闭合线圈上方有一竖直放置的条形磁铁，磁铁的N极朝下。当磁铁向下运动时(但未插入线圈内部)，BSNA(线圈中感应电流的方向与图中箭头方向相同，磁铁与线圈相互吸引B(线圈中感应电流的方向与图中箭头方向相同，磁铁与线圈相互排斥C.线圈中感应电流的方向与图中箭头方向相反，磁铁与线圈相互吸引D(线圈中感应电流的方向与图中箭头方向相反，磁铁与线圈相互排斥3(图中两条平行虚线之间存在匀强磁场，虚线间的距离为l，磁场方向垂直纸面向里。abcd是位于纸面内的梯形线圈，ad与bc间的距离也为l。t=0时刻，bc边与磁场区域边界重合(如图)。现令线圈以恒定的速度v沿垂直于磁场区域边界的方向穿过磁场区域。取沿a?b?c?d?a的感应电流为正，则在线圈穿越磁场区域的过程中，感应电流I随时间t变化的school)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmagazines,firesburntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedinXITangTombrotten"clip"taxes,taxofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedseveralhouses.1938newmorningofSeptember18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagelinetoTungYangJiaQiaoyanTemplewallandmetYangJia溇ZhouDana(male)weeksbecauseoflong-termillnessandcan'tworkinthefields,theJapaneseseehisfacefromscratchwithoutcalluses,regardhimas"Shina",thrustaknifeatthesceneofhisdeath.Thebodywasstabbed7times,wound13.Thesameday,TrangbangvillageheardtheJapanesecometo"mop-up"arehiding,motherof9ZhouGuanbaoZhangAyingtodrilla"drymound",wasdiscoveredbytheJapanese,ashotintheend.Thesameday,is7zhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,theJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleontheRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousand,waterandlandgohandinhand"mop-up"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingitschildNiuJun(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayersJinFuqin,andShenBaosheng,sixpeoplereceivedWujiangundergroundCountyGovernmentnotification图线可能是()4(如图，在一水平放置的平板MN的上方有匀强磁场，磁感应强度的大小为B，磁场方向垂直于纸面向里。许多质量为m带电量为+q的粒子，以相同的速率v沿位于纸面内的各个方向，由小孔O射入磁场区域。不计重力，不计粒子间的相互影响。下列图中阴影部mv分表示带电粒子可能经过的区域，其中。哪R,Bq个图是正确的,()5.如图所示，均强磁场的方向垂直纸面向里，一带电微粒从磁场边界d点垂直与磁场方向射入，沿曲线dpa打到屏MN上的a点，通过pa段用时为t。若该微粒经过p点时，与一个静止的不带电微粒碰撞并结合为一个新微粒，最终打到屏MN上。两个微粒所受重力均忽略。新微粒运动的up"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-randlandgohandinhand"mop,wateheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousandRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktthetheJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleonhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,d.Thesameday,is7zup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrilla"drymound",wasdiscoveredbytheJapanese,ashotintheen-h.Thebodywasstabbed7times,wound13.Thesameday,TrangbangvillageheardtheJapanesecometo"moprustaknifeatthesceneofhisdeattermillnessandcan'tworkinthefields,theJapaneseseehisfacefromscratchwithoutcalluses,regardhimas"Shina",th-ZhouDana(male)weeksbecauseoflong溇oTungYangJiaQiaoyanTemplewallandmetYangJialinetseveralhouses.1938newmorningofSeptember18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagenXITangTombrotten"clip"taxes,taxofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedgazines,firesburntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedischool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmasJinFuqin,andShenBaosheng,sixpeoplereceivedWujiangundergroundCountyGovernmentnotificationchildNiuJun(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayer2A(轨迹为pb，至屏幕的时间将小于tB(轨迹为pc，至屏幕的时间将大于tC(轨迹为pb，至屏幕的时间将等于tD(轨迹为pa，至屏幕的时间将大于t6.图中为一“滤速器”装置示意图。a、b为水平放置的平行金属板，一束具有各种不同速率的电子沿水平方向经小孔O进入a、b两板之间。为了选取具有某种特定速率的电子，可在a、b间加上电压，并沿垂直于纸面的方向加一匀强磁场，使所选电子仍能够沿水平直线OO'运动，由O'射出。不计重力作用。可能达到上述目的的办法是aO'ObA.使a板电势高于b板，磁场方向垂直纸面向里B.使a板电势低于b板，磁场方向垂直纸面向里使a板电势高于b板，磁场方向垂直纸面向外C.D.使a板电势低于b板，磁场方向垂直纸面向外7.如图，在匀强磁场中固定放置一根串接一电阻R的直角形金属导轨aob(在纸面内)，磁场方向垂直纸面朝里，另有两根金属导轨c、d分别平行于oa、ob放置。保持导轨之间接触良好，金属导轨的电阻不计。现经历以下四个过程:?以速率v移动d，使它与ob的距离增大一倍;?再以速率v移动c，使它与oa的距离减小一半;?然后，再以速率2v移动c，使它回到原处;?最后以速率2v移动d，使它也回到原处。设上述四个过程中通过电阻R的电量的大小依次为Q、Q、Q和Q，则1234A.Q,Q,Q,QB.Q,Q,2Q,2Q12341234C.2Q,2Q,Q,QD.Q?Q,Q?Q12341234-ngas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousand,waterandlandgohandinhand"mopGuTouintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktheShanghaidialect,latertobecalledrrested16people,infengqiaocigarettesthismorningbang,killing11peopleontheRiver,EastmeetingpointinwoodqiaothasatoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,theJapanesearmyinYanTombraiding,a"drymound",wasdiscoveredbytheJapanese,ashotintheend.Thesameday,is7zhouhaijiangzhigrandfatherZhouYingbaoup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrill-13.Thesameday,TrangbangvillageheardtheJapanesecometo"mopratchwithoutcalluses,regardhimas"Shina",thrustaknifeatthesceneofhisdeath.Thebodywasstabbed7times,woundtermillnessandcan'tworkinthefields,theJapaneseseehisfacefromsc-ZhouDana(male)weeksbecauseoflong溇metYangJia18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagelinetoTungYangJiaQiaoyanTemplewallandemberofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedseveralhouses.1938newmorningofSeptrntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedinXITangTombrotten"clip"taxes,taxgazines,firesbuschool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmaplereceivedWujiangundergroundCountyGovernmentnotificationn(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayersJinFuqin,andShenBaosheng,sixpeochildNiuJuup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits3db×××××××××××××××c×××××Rao×××××8、电阻R、电容C与一线圈连成闭合电路，条形磁铁静止于线S圈的正上方，N极朝下，如图所示。现使磁铁开始自由下落，Na在N极接近线圈上端的过程中，流过R的电流方向和电容器极板的带电情况是RCA(从a到b，上极板带正电bB(从a到b，下极板带正电C(从b到a，上极板带正电D(从b到a，下极板带正电9(磁场对放入其中的长为l、电流强度为I、方向与磁场垂直的通电导线有力F的作用，可以用磁感应强度B描述磁场的力的性质，磁感应强度的大小B,___________，在物理学中，用类似方法描述物质基本性质的物理量还有___________等。10(取两个完全相同的长导线，用其中一根绕成如图(a)所示的螺线管，当该螺线管中通以电流强度为I的电流时，测得螺线管内中部的磁感应强度大小为B，若将另一根长导线对折后绕成如图(b)所示的螺线管，并通以电流强度也为I的电流时，则在螺线管内中部的磁感应强度大小为()(A)0。(B)0.5B。(C)B。(D)2B。(a)(b)11(如图所示，一带负电的质点在固定的正的点电荷作用下绕该正电荷做匀速圆周运动，周期为T，轨道平面位于纸面0内，质点的速度方向如图中箭头所示。现加一垂直于轨道平面的匀强磁场，已知轨道半径并不因此而改变，则A若磁场方向指向纸里，质点运动的周期将大于T0sJinFuqin,andShenBaosheng,sixpeoplereceivedWujiangundergroundCountyGovernmentnotificationchildNiuJun(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayerup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-randlandgohandinhand"mop,wateheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousandRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktthetheJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleonhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,d.Thesameday,is7zup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrilla"drymound",wasdiscoveredbytheJapanese,ashotintheen-h.Thebodywasstabbed7times,wound13.Thesameday,TrangbangvillageheardtheJapanesecometo"moprustaknifeatthesceneofhisdeattermillnessandcan'tworkinthefields,theJapaneseseehisfacefromscratchwithoutcalluses,regardhimas"Shina",th-ZhouDana(male)weeksbecauseoflong溇oTungYangJiaQiaoyanTemplewallandmetYangJialinetseveralhouses.1938newmorningofSeptember18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagenXITangTombrotten"clip"taxes,taxofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedgazines,firesburntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedischool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandma4B若磁场方向指向纸里，质点运动的周期将小于T0C若磁场方向指向纸外，质点运动的周期将大于T0D若磁场方向指向纸外，质点运动的周期将小于T012(如图所示，在PO、QR区域中存在着磁感应强度大小相等、方向相反的匀强磁场、磁场方向均垂直于纸面。一导线框abcdefa位于纸面内，框的邻边都相互垂直，bc边与磁场的边界P重合，导线框与磁场区域的尺寸如图所示。从t,0时刻开始，线框匀速横穿两个磁场区域。以a?b?c?d?e?f为线框中的电动势ε的正方向，以下四个ε,t关系示意图中正确的是13.如图所示，LOO′T为一折线，它所形成的两个角?LOO′和?OO′L′均为45?。折线的右边有一匀强磁场.其方向垂直于纸面向里.一边长为l的正方形导线框沿垂直于OO′的方向以速度,作匀速直线运动，在t,0的刻恰好位于图中所示位置。以逆时针方向为导线框中电流的正方向，在下面四幅图中能够正确表示电流-时间(,I-t)关系的是(时间以I/为单位)13.Thesameday,TrangbangvillageheardtheJapanesecometo"mopratchwithoutcalluses,regardhimas"Shina",thrustaknifeatthesceneofhisdeath.Thebodywasstabbed7times,woundtermillnessandcan'tworkinthefields,theJapaneseseehisfacefromsc-ZhouDana(male)weeksbecauseoflong溇metYangJia18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagelinetoTungYangJiaQiaoyanTemplewallandemberofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedseveralhouses.1938newmorningofSeptrntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedinXITangTombrotten"clip"taxes,taxgazines,firesbuschool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmaplereceivedWujiangundergroundCountyGovernmentnotificationn(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayersJinFuqin,andShenBaosheng,sixpeochildNiuJuup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-ngas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousand,waterandlandgohandinhand"mopGuTouintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktheShanghaidialect,latertobecalledrrested16people,infengqiaocigarettesthismorningbang,killing11peopleontheRiver,EastmeetingpointinwoodqiaothasatoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,theJapanesearmyinYanTombraiding,a"drymound",wasdiscoveredbytheJapanese,ashotintheend.Thesameday,is7zhouhaijiangzhigrandfatherZhouYingbaoup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrill-514.如图所示，在x轴上方存在着垂直于纸面向里、磁感应强度为B的匀强磁场，一个不计重力的带电粒子从坐标原点O处以速度v进入磁场，粒子进入磁场时的速度方向垂直于磁场且与x轴正方向成120?角，若粒子穿过y轴正半轴后在磁场中到x轴的最大距离为a，则该粒子的比荷和所带电荷的正负是3vvA.，正电荷B.，正电荷2aB2aB3vvC.，负电荷D.，负电荷2aB2aB15(如图所示，矩形线圈abcd在匀强磁场中可以分别绕垂直于磁场方向的轴P和P以相同的角速度匀速转动，当线圈平面转到与磁场方向平行时12A(线圈绕P转动时的电流等于绕P转动时的电流12B(线圈绕P转动时的电动势小于绕P转动时的电动势12C(线圈绕P和P转动时电流的方向相同，都是a?b?c?d12D(线圈绕P转动时dc边受到的安培力大于绕P转动时dc边受到的12安培力16(如图所示，长方形abcd长ad=0(6m，宽ab=0(3m，0、e分别是ad、bc的中点，以ad为直径的半圆内有垂直纸面向里的匀强磁场(边界上无磁—7场)，磁感应强度B=0(25T。一群不计重力、质量m=3×10kg、电荷量—32vq=+2×10C的带电粒子以速度=5×10m,s沿垂直ad方向且垂直于磁场,wateheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousandRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktthetheJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleonhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,d.Thesameday,is7zup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrilla"drymound",wasdiscoveredbytheJapanese,ashotintheen-h.Thebodywasstabbed7times,wound13.Thesameday,TrangbangvillageheardtheJapanesecometo"moprustaknifeatthesceneofhisdeattermillnessandcan'tworkinthefields,theJapaneseseehisfacefromscratchwithoutcalluses,regardhimas"Shina",th-ZhouDana(male)weeksbecauseoflong溇oTungYangJiaQiaoyanTemplewallandmetYangJialinetseveralhouses.1938newmorningofSeptember18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagenXITangTombrotten"clip"taxes,taxofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedgazines,firesburntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedischool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmasJinFuqin,andShenBaosheng,sixpeoplereceivedWujiangundergroundCountyGovernmentnotificationchildNiuJun(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayerup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-randlandgohandinhand"mop6射人磁场区域A(从Od边射入的粒子，出射点全部分布在Oa边B(从aO边射入的粒子，出射点全部分布在Ob边C(从Od边射入的粒子，出射点分布在Oa边和ab边D(从aO边射入的粒子，出射点分布在ab边和be边17(如图所示,接有灯泡L的平行金属导轨水平放置在匀强磁场中，一导体杆与两导轨良好接触并做往复运动,其运动情况与弹簧振子做简谐运动的情况相同。图中O位置对应于弹簧振子的平衡位置,P、Q两位置对应于弹簧振子的最大位移处。若两导轨的电阻不计，则A(杆由O到P的过程中，电路中电流变大B(杆由P到Q的过程中，电路中电流一直变大C(杆通过O处时，电路中电流方向将发生改变D(杆通过O处时，电路中电流最大18(在竖直向上的匀强磁场中，水平放置一个不变形的单匝金属圆线圈，规定线圈中感应电流的正方向如图1所示，当磁场的磁感应强度B随时间t如图2变化时，图3中正确表示线圈中感应电动势E变化的是19(如图所示，位于一水平面内的、两根平行的光滑金属导轨，处在匀强磁场中，磁场方向垂直于导轨所在的平面，导轨的一端与一电阻相连;具有一定质量的金属杆ab放在导轨上并与导轨垂直。现用一平行于导轨的恒力F拉杆ab，使它由静止开始向右运动。杆和导轨的电阻、感应电流产生的磁场均可不计。用E表示回路中的感应电动势，i表示回路中的感应电流，在i随时间增大的过程中，电阻消耗的功率a"drymound",wasdiscoveredbytheJapanese,ashotintheend.Thesameday,is7zhouhaijiangzhigrandfatherZhouYingbaoup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrill-13.Thesameday,TrangbangvillageheardtheJapanesecometo"mopratchwithoutcalluses,regardhimas"Shina",thrustaknifeatthesceneofhisdeath.Thebodywasstabbed7times,woundtermillnessandcan'tworkinthefields,theJapaneseseehisfacefromsc-ZhouDana(male)weeksbecauseoflong溇metYangJia18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagelinetoTungYangJiaQiaoyanTemplewallandemberofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedseveralhouses.1938newmorningofSeptrntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedinXITangTombrotten"clip"taxes,taxgazines,firesbuschool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmaplereceivedWujiangundergroundCountyGovernmentnotificationn(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayersJinFuqin,andShenBaosheng,sixpeochildNiuJuup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-ngas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousand,waterandlandgohandinhand"mopGuTouintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktheShanghaidialect,latertobecalledrrested16people,infengqiaocigarettesthismorningbang,killing11peopleontheRiver,EastmeetingpointinwoodqiaothasatoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,theJapanesearmyinYanTombraiding,7等于A(F的功率B(安培力的功率的绝对值C(F与安培力的合力的功率D(iE20(图为云室中某粒子穿过铅板P前后的轨迹，室中匀强磁场的方向与轨迹所在平面垂直(图中垂直于纸面向里，)由此可知此粒子A一定带正电B一定带负电C不带电D可能带正电，也可能带负电21(如图所示，A、B为大小、形状均相同且内壁光滑，但用不同材料制成的圆管，竖直固定在相同高度。两个相同的磁性小球，同时从A、B管上端的管口无初速释放，穿过A管的小球比穿过B管的小球先落到地面。下面对于两管的描述中可能正确的是AA管是用塑料制成的，B管是用铜制成的BA管是用铝制成的，B管是用胶木制成的CA管是用胶木制成的，B管是用塑料制成的DA管是用胶木制成的，B管是用铝制成的,,,0,介子衰变的方程为K?π+π，其中K介22(K,0子和π介子带负的基元电荷，π介子不带电，一个K介子沿垂直于磁场的方向射入匀强磁,场中，其轨迹为圆弧AP。衰变后产生的π介子的轨迹为圆弧PB，两轨迹在P点相切，它们的半径Rπ,0与R之比为2:1。π介子的轨迹未画出。由此可知ππ0的动量大小与π的动量大小之比为A(1:1B(1:2C(1:3D(1:623，如图所示，一个有界匀强磁场区域，磁场方向垂直纸面向外(一个矩形闭合导线框abcd，沿纸面由位置1(左)匀速运动到位置2(右)(则(A)导线框进入磁场时，感应电流方向为a?b?c?d?a(B)导线框离开磁场时，感应电流方向为a?d?c?b?a(C)导线框离开磁场时，受到的安培力方向水平向右(D)导线框进入磁场时(受到的安培力方向水平向左24(如图，一个边长为l的正方形虚线框内有垂直于纸面向里的匀强磁场;一个边长也为l的正方形导线框所在平面与磁场方向垂直;虚线框对角线ab与导线框的一条边垂直，ba的延长线平分导线框。在t,0时，up"arehiding,motherof9ZhouGuanbaoZhangAyingtodrilla"drymound",wasdiscoveredbytheJapanese,ashotintheen-h.Thebodywasstabbed7times,wound13.Thesameday,TrangbangvillageheardtheJapanesecometo"moprustaknifeatthesceneofhisdeattermillnessandcan'tworkinthefields,theJapaneseseehisfacefromscratchwithoutcalluses,regardhimas"Shina",th-ZhouDana(male)weeksbecauseoflong溇oTungYangJiaQiaoyanTemplewallandmetYangJialinetseveralhouses.1938newmorningofSeptember18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagenXITangTombrotten"clip"taxes,taxofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedgazines,firesburntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedischool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmasJinFuqin,andShenBaosheng,sixpeoplereceivedWujiangundergroundCountyGovernmentnotificationchildNiuJun(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayerup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-randlandgohandinhand"mop,wateheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousandRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktthetheJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleonhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,d.Thesameday,is7z8使导线框从图示位置开始以恒定速度沿ab方向移动，直到整个导线框离开磁场区域。以i表示导线框中感应电流的强度，取逆时针方向为正。下列表示i—t关系的图示中，可能正确的是d固定在匀强磁场中，磁感线的方向与导线框所在平面垂直。规定磁场25.矩形导线框abc的正方向垂直纸面向里，磁感应强度B随时间变化的规律如图所示.若规定顺时针方向为感应电流I的正方向，下列各图中正确的是13.Thesameday,TrangbangvillageheardtheJapanesecometo"mopratchwithoutcalluses,regardhimas"Shina",thrustaknifeatthesceneofhisdeath.Thebodywasstabbed7times,woundtermillnessandcan'tworkinthefields,theJapaneseseehisfacefromsc-ZhouDana(male)weeksbecauseoflong溇metYangJia18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagelinetoTungYangJiaQiaoyanTemplewallandemberofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedseveralhouses.1938newmorningofSeptrntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedinXITangTombrotten"clip"taxes,taxgazines,firesbuschool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmaplereceivedWujiangundergroundCountyGovernmentnotificationn(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayersJinFuqin,andShenBaosheng,sixpeochildNiuJuup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-ngas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousand,waterandlandgohandinhand"mopGuTouintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktheShanghaidialect,latertobecalledrrested16people,infengqiaocigarettesthismorningbang,killing11peopleontheRiver,EastmeetingpointinwoodqiaothasatoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,theJapanesearmyinYanTombraiding,a"drymound",wasdiscoveredbytheJapanese,ashotintheend.Thesameday,is7zhouhaijiangzhigrandfatherZhouYingbaoup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrill-926.在如图所示的空间中，存在场强为E的匀强电场，同时存在沿x轴负方向，磁感应强度为B的匀强磁场。一质子(电荷量为e)在该空间恰沿y轴正方向以速度v匀速运动。据此可以判断出A.质子所受电场力大小等于eE,运动中电势能减小;沿z轴正方向电势升高B.质子所受电场力大小等于eE,运动中电势能增大;沿z轴正方向电势降低C.质子所受电场力大小等于evB,运动中电势能不变;沿z轴正方向电势升高thetheJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleonhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,d.Thesameday,is7zup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrilla"drymound",wasdiscoveredbytheJapanese,ashotintheen-h.Thebodywasstabbed7times,wound13.Thesameday,TrangbangvillageheardtheJapanesecometo"moprustaknifeatthesceneofhisdeattermillnessandcan'tworkinthefields,theJapaneseseehisfacefromscratchwithoutcalluses,regardhimas"Shina",th-ZhouDana(male)weeksbecauseoflong溇oTungYangJiaQiaoyanTemplewallandmetYangJialinetseveralhouses.1938newmorningofSeptember18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagenXITangTombrotten"clip"taxes,taxofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedgazines,firesburntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedischool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmasJinFuqin,andShenBaosheng,sixpeoplereceivedWujiangundergroundCountyGovernmentnotificationchildNiuJun(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayerup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-randlandgohandinhand"mop,wateheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousandRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeakt10D.质子所受电场力大小等于evB,运动中电势能不变;沿z轴正方向电势降低27(如图所示，平行于y轴的导体棒以速度v向右做匀速直线运动经过半径为R、磁感应强度为B的圆形匀强磁场区域导体棒中的感应电动势ε与导体棒位置x关系的图像是28(如图所示，水平面内有一平行金属导轨，导轨光滑且电阻不计。匀强磁场与导轨一闪身垂直。阻值为R的导体棒垂直于导轨静止放置，且与导轨接触。T=0时，将形状S由1掷到2。Q、i、v和a分别表示电容器所带的电荷量、棒中的电流、棒的速度和加速度。下列图象正确的是29如图，两根相互平行的长直导线分别通有方向相反的电流和，且;a、b、c、IIII,1212d为导线某一横截面所在平面内的四点，且a、b、c与两导线共面;b点在两导线之间，b、d的连线与导线所在平面垂直。磁感庳强度可能为零的点是A.a点B.b点C.c点D.d点30.为了解释地球的磁性，19世纪安培假设:地球的磁场是由绕过地心的轴的环形电流I引起的。在下列四个图中，正确表示安培假设中环形电流方向的是13.Thesameday,TrangbangvillageheardtheJapanesecometo"mopratchwithoutcalluses,regardhimas"Shina",thrustaknifeatthesceneofhisdeath.Thebodywasstabbed7times,woundtermillnessandcan'tworkinthefields,theJapaneseseehisfacefromsc-ZhouDana(male)weeksbecauseoflong溇metYangJia18,theJapaneseteamwenttothecountryside"sweep"fromthekaiyangvillagelinetoTungYangJiaQiaoyanTemplewallandemberofficerslivein8ofYanDongvillagefarmershome,troopsatnight,Yaowasburnedseveralhouses.1938newmorningofSeptrntdown.In1938,theJapaneselearnedthatthenationalGovernmentestablishedinXITangTombrotten"clip"taxes,taxgazines,firesbuschool)],44housebuildingaswellasmorethan1000copiesofbooks,morethan10kindsofcollectionofnewspapersandmaplereceivedWujiangundergroundCountyGovernmentnotificationn(strictTombseventhdistrictChang)andtheDistrictAssistantYuXuchu,andplayersJinFuqin,andShenBaosheng,sixpeochildNiuJuup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-ngas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousand,waterandlandgohandinhand"mopGuTouintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktheShanghaidialect,latertobecalledrrested16people,infengqiaocigarettesthismorningbang,killing11peopleontheRiver,EastmeetingpointinwoodqiaothasatoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,theJapanesearmyinYanTombraiding,a"drymound",wasdiscoveredbytheJapanese,ashotintheend.Thesameday,is7zhouhaijiangzhigrandfatherZhouYingbaoup"arehiding,motherof9ZhouGuanbaoZhangAyingtodrill-1131.电磁轨道炮工作原理如图所示。待发射弹体可在两平行轨道之间自由移动，并与轨道保持良好接触。电流I从一条轨道流入，通过导电弹体后从另一条轨道流回。轨道电流可形成在弹体处垂直于轨道面得磁场(可视为匀强磁场)，磁感应强度的大小与I成正比。通电的弹体在轨道上受到安培力的作用而高速射出。现欲使弹体的出射速度增加至原来的2倍，理论上可采用的方法是A.只将轨道长度L变为原来的2倍B.只将电流I增加至原来的2倍C.只将弹体质量减至原来的一半D.将弹体质量减至原来的一半，轨道长度L变为原来的2倍，其它量不变32.如图甲所示，两固定的竖直光滑金属导轨足够长且电阻不计。两质量、长度dh均相同的导体棒、，置于边界水平的匀强磁场上方同一高度处。磁场宽为ch3，方向与导轨平面垂直。先由静止释放，刚进入磁场即匀速运动，此时ccd再由静止释放，两导体棒与导轨始终保持良好接触。用a表示的加速度，Ecckddd表示的动能，x、x分别表示、相对释放点的位移。图乙中正确的是ccdup"jiaxingareawestoftherailway,YanTombareafall.March6,NiuShan(CountyGovernmentIIsectionchief)carryingits-randlandgohandinhand"mop,wateheShanghaidialect,latertobecalledGuTongas"killleft."OnJanuary18,1943,theelves,fivethousandorsixthousandRiver,Eastmeetingpointinwoodqiaotuintheafternoonkilling4peopleontheRiverside.GuTongisaJapanesegospeaktthetheJapanesearmyinYanTombraiding,hasarrested16people,infengqiaocigarettesthismorningbang,killing11peopleonhouhaijiangzhigrandfatherZhouYingbaotoescapetheJapanesearmy,wasfoundontheroad,ashotintheend.InMarch1939,d.Thesameday,is7