试题与答案

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

题型:选择题

题目:

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,粒子进人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(  )

A.,正电荷

B.,正电荷

C.,负电荷

D.,负电荷

答案:

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参考答案:A,B,D解析: 本题考查的知识点是低渗性脱水的病情评估。[要点透析] 轻度缺钠时,病人头晕、手足麻木、口渴不明显;中度缺钠时,病人常有恶心、呕吐、血压不稳定;重度缺钠时,病人神志不清、肌腱反射...

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