2014高考物理名师指导分项拿分专训-易错专训：专题3 电场与磁场(新题含解析)

2014高考物理名师指导分项拿分专训-易错专训：专题3 电场与磁场(新题含解析) 易错专训(三) 电场与磁场 【基础回顾】 F 1(在公式E,中，误认为E与F成正比、与q成反比( q Q 2(在公式C,中，误认为C与Q成正比、与U成反比( U 3(误认为带电粒子的运动轨迹与电场线重合( 4(在电场中误认为场强大的地方电势高( QεSr5(不能正确区分C,和C,的意义及用途( U4πkd F 6(在公式B,中，误认为B与F成正比、与IL成反比( IL 7(判断安培力方向时，将左手定则和右手定则混淆( 8(判断负电荷在磁场中运动受力时，将“四指”指向用错( the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 【纠错提升】 1((2013?保定调研)某静电场中的一条电场线与x轴重合，其电势的变化规律如图所示(在O点由静止释放一个负点电荷，该负点电荷仅受电场力的作用，则在,x,x区间内( ) 00 A(该静电场是匀强电场 B(该静电场是非匀强电场 C(负点电荷将沿x轴正方向运动，加速度不变 D(负点电荷将沿x轴负方向运动，加速度逐渐减小 the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 答案 八年级地理上册填图题岩土工程勘察试题省略号的作用及举例应急救援安全知识车间5s试题及答案 :AC 解析:图线的斜率大小等于电场中电场强度的大小～故该条电场线上各点场强一样～该静电场为匀强电场～A正确～B错误,沿着电场线的方向电势降低～可知静电场方向沿x轴负方向～故负点电荷沿x轴正方向运动～其受到的电场力为恒力～由牛顿第二定律可知其加速度不变～C正确～D错误( 2(如图所示，AOB为一边界为四分之一圆的匀强磁场，O点为圆心，D点为边界OB的中点，C点为边界上一点，且CD?AO.现有两个完全相同的带电粒子以相同的速度射入磁场(不计粒子重力)，其中粒子1从A点正对圆心射入，恰从B点射出，粒子2从C点沿CD射入，从某点离开磁场，则可判断( ) A(粒子2在BC之间某点射出磁场 B(粒子2必在B点射出磁场 C(粒子1与粒子2在磁场中的运行时间之比为3?2 D(粒子1与粒子2的速度偏转角度应相同 the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 答案:BC 解析:本题考查带电粒子在磁场中的运动(粒子1从A点射入磁场～将从B点射出～粒子在磁场中运动的圆心角为90?～运动的半径等于BO～粒子2从C点射入时其轨迹如图所示～设对应的圆心为O～运动的半径也为BO～连接OC、OB～由几何知识知～OCOB1111为平行四边形～则OB,CO～则粒子2一定从B点射出磁场～A错1 误～B正确,连接PB～易知P为OC的中点～从而易求?BOP,1160?～因此两粒子的速度偏转角不同～且两粒子在磁场中的运行时间之比即为两粒子的速度偏转角之比～即为90??60?,3?2～C正确～D错误( the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 3(利用如图所示的方法可以测得金属导体中单位体积内的自由电子数n，现测得一块横截面为矩形的金属导体的宽为b，厚为d，并加有与侧面垂直的匀强磁场B，当通以图示方向电流I时，在导体上、下表面间用电压表可测得电压为U.已知自由电子的电荷量为e，则下列判断正确的是( ) ?上表面电势高 ?下表面电势高 I ?该导体单位体积内的自由电子数为 edb BI ?该导体单位体积内的自由电子数为 eUb A(?? B(?? C(?? D(?? the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 答案:B 解析:画出平面图如图所示～由左手定则可知～ 自由电子向上表面偏转～故下表面电势高～故选项?正确～?错 UBI 误,再根据e,evB～I,neSv,nebdv得n,～故选项?正确～deUb ?错误( 4(示波管的内部结构如图甲所示(如果偏转电极XX′、YY′之间都没有加电压，电子束将打在荧光屏中心(如果在偏转电极XX′之间和YY′之间加上图丙所示的几种电压，荧光屏上可能会出现图乙中(a)、(b)所示的两种波形(则( ) the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote A(若XX′和YY′分别加电压(3)和(1)，荧光屏上可以出现图乙中(a)所示波形 B(若XX′和YY′分别加电压(4)和(1)，荧光屏上可以出现图乙中(a)所示波形 C(若XX′和YY′分别加电压(3)和(2)，荧光屏上可以出现图乙中(b)所示波形 D(若XX′和YY′分别加电压(4)和(2)，荧光屏上可以出现图乙中(b)所示波形 the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 答案:AC 解析:要使荧光屏上出现图乙中(a)所示波形～XX′加扫描电压(3)和YY′加正弦电压(1)～则A正确,要使荧光屏上出现图乙中(b)所示波形～XX′加扫描电压(3)和YY′加方波电压(2)～则C正确( 5(如图所示，中轴线PQ将矩形区域MNDC分成上、下两部分，上部分充满垂直纸面向外的匀强磁场，下部分充满垂直纸面向里的匀强磁场，磁感应强度皆为B.一质量为m、带电荷量为q的带正电的粒子从P点进入磁场，速度与边MC的夹角θ,30?.MC边长为a，MN边长为8a，不计粒子重力(求: (1)若要该粒子不从MN边射出磁场，其速度最大是多少, (2)若要求该粒子恰从Q点射出磁场，其在磁场中的运行时间最少是多少, the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote qBa10πm 答案:(1) (2) m3qB 解析:(1)设粒子恰不从MN边射出磁场时的轨迹半径为r～由几何关系得 1rcos 60?,r,a～解得r,a 2 2v又由qvB,m r qBa 解得最大速度v,. maxm (2)粒子每经过分界线PQ一次～在PQ方向前进的位移为轨迹半径r的3倍 设粒子进入磁场后第n次经过PQ线时恰好到达Q点 有n×3r,8a 8解得n,,4.62 3 n所能取的最小自然数为5 2πm 粒子做圆周运动的周期为T, qB 粒子每经过PQ分界线一次用去的时间为 2πm1t,T, 33qB 10πm 粒子到达Q点的最短时间为t,5t,. min3qB 6(质谱仪是由加速电场(两板间电压为U)、速度选择器和偏转1 场组成的，偏转场(边长为L的正方形区域)可以是匀强电场，也可以是匀强磁场(如图所示，已知不计初速度的正元电荷电荷量为e、质量为m，经加速电场加速后刚好沿直线经过速度选择器并从ac边中点进入偏转场(若在ab、cd两板间加上电压U，放在ab板右端的3 the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote 探测仪刚好能接收到信号( E2(1)求速度选择器的电场强度与磁感应强度的比值; B2 (2)求ab、cd两板间所加电压U的值; 3 (3)若在偏转区域没有电场，只加匀强磁场，欲使探测仪能接收 到信号，求所加磁场的磁感应强度( the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote em2U2U411答案:(1) (2)2U (3) 1me5L 解析:(1)带电粒子在加速电场中加速的过程中～根据动能定理 12有Ue,mv? 12 带电粒子经过速度选择器～根据共点力的平衡条件有 Ee,evB? 22 Ee2U21联立??得,, mB2 (2)带电粒子在偏转电场中做类平抛运动～有 L,vt? LUe132,t? Lm22 联立???得U,2U, 31 (3)带电粒子在偏转磁场中做匀速圆周运动～设轨道半径为R～ 由几何知识得 L,,222,,L，R,,R? ,,2 2mv 根据牛顿第二定律有evB,? R 2Um41联立???得B, e5L 根据左手定则～B的方向垂直纸面向里( the three. Third, seriously implement the Central, provincial, municipal and County party Committee on the establishment of a sound work style construction views of the long-acting mechanism and on the implementation of the three Suns calls for further strengthening of education administration and supervision of party members and cadres, from the ... Accept supervision and earnestly grasp, balance, two promotion, important job himself, the Secretary of development, major issues personally. 5. strongly supports accountability discipline discipline. Administrative provisions on strict enforcement of party members and cadres to ask all the discipline inspection and supervision cadres in accordance with the iron itself must be a hard requirement, adhere to the responsibilities and play, earnestly fulfill their duties of supervision and accountability for Zhi JI. Zhen into full play and the oversight role of the Commission, establish and improve the village rules and community conventions, promoting joint public and serving the sunshine publicly available implementation of the platform for action. Discipline in handling cases, adhere to find along with scrutiny, to appoint the interference and resistance, backed by courageous, find the problem corrected, powerful maintenance the seriousness of responsibility of uncorrupted. Actively promote the discipline Committee detailed switch and, casting, tree-generating activities. Promote