章节大纲

  • 常规

    全部折叠 展开全部

  • 电压

    Tesla coils producing electrical arcs with vibrant light and sound effects at night.

    Often the star of science shows and museum installments, Tesla coils create magnificent displays of light and sound. They have low electrical current but incredibly large electric potentials. 
    ::通常,Tesla coils是科学展和博物馆分期展的明星,它们创造出光和声音的辉煌展示。它们电流低,但电潜力大得令人难以置信。

    The Electric Potential in a Uniform Field
    ::统一战地的电力潜力

    Electric Potential
    ::电能潜能

    In the study of mechanics, the concept of , and the conservation thereof, was extremely useful. The same will be true for the study of electrical interactions. The work done moving a charged particle in an electric field can result in the particle gaining or losing both kinetic and .
    ::在机械学研究中,......的概念及其保护极为有用,对电子相互作用的研究也是如此,在电场移动充电粒子的工作可能导致粒子的进化或失去动力和动力。

    Lifting an object in a gravitational field requires work and increases the object's potential energy. A similar situation occurs when you move two charged objects relative to each other. We already know that each object has an electric field surrounding it, which affects the other charge. If the two charged objects have the same charge, they repel each other. Moving these two objects closer to each other requires working against the repulsive force, which increases the potential energy of the system. Conversely, moving two like charges apart will decrease the potential energy. If the objects attract each other, the opposite situations occur: if you pull them apart, you do work against the force, which increases the potential energy of the system, but bringing attractive charges closer together decreases the potential energy.
    ::在引力字段中抬起物体需要工作并增加物体的潜在能量。 当您移动两个相相对的充电对象时, 也会出现类似的情况。 我们已经知道每个物体周围都有电场, 从而影响到另一物体。 如果两个充电对象有相同的电场, 它们就会互相击退。 把这两个物体拉近彼此, 就需要与令人厌恶的力量相对应, 这会增加系统的潜在能量。 相反, 将两个物体分开移动会减少潜在的能量。 如果两个物体相互吸引, 就会发生相反的情况: 如果把它们分开, 你的确会与电力对抗, 这会增加系统的潜在能量, 但引力会相互接近, 但却会让吸引的电源更接近, 减少潜在的能量 。

    It is often easy to think of the change in energy as a mountain or an inverted cone, depending on the situation. Imagine a positive point charge, with the corresponding electric field around it. If you are moving another positive point charge, the situation is like a mountain, with the original point charge at the peak. As the second charge moves towards the first, it must go up the mountain. This requires work, and increases the potential energy of the system. If, however, the second charge is a negative point charge, the two charges attract each other and the situation is like a cone: the second charge easily falls towards the first, decreasing the potential energy. It would then require work to get the second charge up and out of the cone, away from the first charge.
    ::通常很容易将能量变化想象成一座山或一座逆向锥体,视情况而定。 想象一个正点充电, 其周围有相应的电场。 如果您移动另一个正点充电, 情况就像一座山, 最初的点充电在顶峰。 当第二点充电转向第一个山时, 它必须上山。 这需要工作, 并增加系统的潜在能量。 但是, 如果第二点充电是负点充电, 这两种充电相互吸引, 情况就像一个锥体: 第二点充电很容易落在第一个山上, 减少潜在的能量。 然后需要工作才能把第二点充电调出锥体, 远离第一个电流。

    Uniform Electric Fields
    ::统一电场

    As we know from , the electric field around a point charge decreases as the from the point increases. However, it is possible to create a constant electric field between two large, flat conducting plates parallel to each other. If one of the plates is positively charged and the other negatively charged, the space between the plates will have a constant electric field except near the edges of the plates.
    ::据我们所知,一个点充电场周围的电场随着点数的增加而减少。 但是,在两个大、平坦的平行操控板块之间可以建立一个固定的电场。 如果一个盘子是正充电的,另一个负充电,盘子之间的空间将有一个固定的电场,但靠近盘子边缘的除外。

    Parallel Plates With A Uniform Electric Field Between Them And Charge Annotations.

    Voltage , which measures the electric potential difference across two points, based on the unit volt (V). To measure the voltage across some distance, it is necessary to pick a position to be the relative zero, because voltage is the change in potential difference. Any point in a system can be given the value of zero volts, but it is typically the point of a point charge or one plate in a uniform electric field as shown above. The voltage is   commonly referred to as the electric potential difference and can be measured using a voltmeter . 
    ::电压根据单位伏(V)测量两个点的电源潜在差异。 要测量某一距离的电压,必须选择一个位置为相对零,因为电压是潜在差异的变化。一个系统中的任何点都可以给定零伏值,但典型的点充电点或一个板块在上文显示的统一电场中。电压通常被称为电的潜在差异,可以用一个电压计测量。

    The electrical potential difference between the two plates is expressed as V = E d , the electric field strength times the distance between the plates. The units in this expression are Newtons/coulomb times meters, which gives the final units Joules/coulomb. Voltage is an expression of the amount of potential energy per unit charge. The work done moving a charge against the field can be calculated by multiplying the electric field potential by the charge, W = V q .
    ::电场强度乘以电板之间的距离。 表达式中的单位为牛顿/ coulomb乘以米, 表示最后的单位为Joules/ coulomb。 电压表示每个单位电荷的潜在能量量。 对电场充电的工程可以通过电场的电荷( W=Vq)乘以电场潜力来计算。

    Examples
    ::实例

    Example 1
    ::例1

    Two large parallel metal plates are 5.0 cm apart. The magnitude of the electric field between them is 800. N/C.
    ::两个大的平行金属板块相隔5.0厘米,中间的电场大小为800厘米。

    (a) What is the potential difference between the plates?
    :伤心a) 车牌之间可能有什么差别?

    (b) What work is done when one electron is moved from the positive to the negative plate?
    :伤心b) 当一个电子从正数板移到负数板时,做了哪些工作?

     

    (a) V = E d = ( 800.   N / C ) ( 0.050   m ) = 40.   J / C = 40.   V
    :伤心a) V=Ed=(800.N/C(0.050米)=40.J/C=40.V)

    (b) W = V q = ( 40.0   J / C ) ( 1.6 × 10 − 19   C ) = 6.4 × 10 − 18   J
    :伤心b) W=Vq=(40.0 J/C)(1.6x10-19 C)=6.4x10-18 J

    Example 2  
    ::例2

    A voltmeter measures the potential difference between two large parallel plates to be 50.0 volts. The plates are 3.0 cm apart. What is the magnitude of the electric field strength between the plates?
    ::电压计测量两个大型平行板块之间的潜在差值为50.0伏。这些板块相隔3.0厘米。板块之间的电场强度有多大?

    E = V d = 50.0   v o l t s 0.030   m = 1700   N / C
    ::E=Vd=50.0伏特0.030米=1700 N/C

    Have you ever wondered what causes lightning to strike? Launch the simulation below and adjust the Charge Separation slider to high, the Cloud Separation slider to low, and be sure to turn the Lightning Rod on (to protect the people in the building). Then, press play and see what happens:
    ::您是否想知道是什么原因导致闪电袭击? 在下面启动模拟,并将电荷分离滑动器调整到高点,将云分离滑动器调整到低点,并确保打开闪电滑动器(以保护大楼里的人)。然后按下播放,看看会发生什么:

    Further Reading
    ::继续阅读

    Summary
    ::摘要

    • The work done moving a charged particle in an electric field can result in the particle gaining or losing both kinetic and potential energy.
      ::在电场移动充电粒子的工作可能导致粒子获得或失去动能和潜在能量。
    • The difference in electric potential energy is measured with a voltmeter in units called volts.
      ::电潜能能量的差异用一个电压计测量,单位称为伏。
    • A constant electric field can be produced by placing two large flat conducting plates parallel to each other.
      ::固定电场可以通过将两个大平板的电路盘平行地放置在一起来生产。
    • The electrical potential difference in a uniform electric field is given as  V = E d .
      ::统一电场的电力潜力差异以V=Ed表示。
    • The work done moving a charge against the field can be found by  W = V q .
      ::W=Vq可以找到向外地收取费用的工作。

    Review
    ::回顾

    1. Two large parallel plates are 0.00630 m apart and the voltage across them is 10.0 volts. What is the electric field strength between the plates?
      ::两块大型平行板块相隔0.00630米,横穿两块板块的电压为10.0伏。两块板块之间的电场强度是多少?
    2. The potential difference between points A and B in an electric field is 25.0 volts. How much work is required to transfer 10.0 coulombs of charge from A to B?
      ::A点和B点在电场中的潜在差别是25.0伏。 将A至B的10.0个电荷库需要多少工作?
    3. 10.0 J of work are required to transfer 2.00 coulombs of charge from point X to point Y in an electric field.  What is the difference in potential between these two points?
      ::10.0 J要求将电场的2.00支电荷从X点转移到Y点。 这两个点之间的潜力有什么区别?
    4. The electric field between two parallel plates connected to a 45 V battery (which produces a 45 V difference in potential between the plates) is 1500 N/C. How far apart are the plates?
      ::连接到45V电池组的两个平行板块之间的电场为1500 N/C。 板块相距多远?
    5. How much kinetic energy will an electron gain if it accelerates through a potential difference of 23,000 volts in a cathode ray tube?
      ::如果电子通过阴极射线管中23 000伏的潜在差速加速加速,它将获得多少动能?

    Explore More
    ::探索更多

    Use this resource to answer the questions that follow.
    ::使用此资源回答下面的问题 。

     

    1. If you do work to move a charged object in an electric field, where does the work go?
      ::如果您确实在电场中工作移动充电物体,工作去向何方?
    2. Points A and B in an electric field have a difference in potential energy.  This difference in electrical potential energy is called ___________________.
      ::电场A点和B点在潜在能源方面有差异。