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正确理解和掌握电场强度和电势这两个概念及有关规律,是学好静电学的关键.一、电场强度和电势电场强度是矢量,有大小、方向,其方向规定为正电荷所受电场力的方向.电场中某点的场强大小、方向是客观存在的,与该点是否放有电荷(试验电荷)无关;电势是标量,有大小、有正负之分,只有相对意义,要描述电场各点电势,必须预先规定某处电势为零之后才能确定.在理论研究中,常取无穷远处的电势为零,在实际应用中常取大地的电势为零,电场中各点电势的正负就是对所规定的零电势参考点而言.电势是由电场本身性质决定的,与该点是否放有电荷(试验电荷)无关.
Correctly understanding and grasping the two concepts of electric field strength and electric potential and related laws is the key to studying electrostatics well. First, electric field strength and potential electric field strength are vectors, which have magnitude and direction, and their direction is defined as the electric field force to which the positive electric charge is subjected. Direction. The magnitude and direction of the field strength at a certain point in the electric field are objectively present, independent of whether or not the point has a charge (test charge); the potential is a scalar quantity, has size, has positive and negative division, and has only relative significance, to describe the electric field. The potential at each point must be specified in advance at a potential of zero. In theoretical studies, the potential at infinity is often taken as zero. In practice, the potential of the earth is often taken as zero, and the potential of each point in the field is positive and negative. It is that for the specified zero potential reference point, the potential is determined by the nature of the electric field itself, and is independent of whether the point has a charge (test charge).