章节大纲

  • 常规

    全部折叠 展开全部

  • 仪表和伏表

    Control room interior for a space shuttle launch, featuring multiple control stations and meters.

    This photo is of the interior of the control room for a space shuttle launch.  Each of these stations has a specific role to play in the launch but they all have something in common. Each station has many meters that are reading or current to show the operators important information they need to safely launch the shuttle.
    ::这张照片是航天飞机发射控制室的内部,每个站点在发射中都有特定的作用,但它们都有共同之处。每个站点都有许多计数计数的读数或时速,向操作者展示安全发射航天飞机所需的重要信息。

    Ammeters and Voltmeters
    ::仪表和伏表

    Ammeters and voltmeters are cleverly designed for the way they are used. Ammeters measure the current of a , and voltmeters measure the voltage drop across a resistor. It is important in the design and use of these meters that they don't change the circuit in such a way as to influence the readings. While both types of meters are technically resistors, they are specifically designed to make their readings without changing the circuit itself.
    ::光量计和电压计的设计非常巧妙。 光量计测量一个电流, 电压计测量电压跌过一个阻力器。 在设计和使用这些电表时,重要的是它们不能以影响读数的方式改变电路。 虽然这两种电表都是技术上的阻力器,但它们是专门设计用来在不改变电路本身的情况下进行读数的。

    Ammeters And Voltmeters In A Circuit With Resistances Labeled.

    Ammeter
    ::毫米

    An ammeter measures the current traveling through the circuit. They are designed to be connected to the circuit in series, and have an extremely low . If an ammeter were connected in parallel, all of the current would go through the ammeter and very little through any other resistor. As such, it is necessary for the ammeter to be connected in series with the resistors. This allows the ammeter to accurately measure the current flow without causing any disruptions. In the circuit sketched above, the ammeter is @$\begin{align*}m_2\end{align*}@$ .
    ::用于测量电路中的电流。 它们设计成可以与电路连成序列, 并且非常低 。 如果一个电路同时连接, 所有的电流都会穿过该仪, 而通过任何其他阻力器的电流将很少。 因此, 需要将该仪与阻力器连成序列。 这使得该仪能够精确测量电流, 而不造成任何干扰 。 在上文绘制的电路中, 仪数是 @ $\ begin{ align\\\\\\\\\\\\\\\\\\ end\\\\ aliign\\\ $ 。 @ $ $ $ 。

    Voltmeter
    ::伏特计

    In contrast, a voltmeter is designed to be connected to a circuit in parallel, and has a very high resistance. A voltmeter measures the voltage drop across a resistor, and does not need to have the current travel through it to do so. When a voltmeter is placed in parallel with a resistor, all the current continues to travel through the resistor, avoiding the very high resistance of the voltmeter. However, we know that the voltage drop across all resistors in parallel is the same, so connecting a voltmeter in parallel allows it to accurately measure the voltage drop. In the sketch, the voltmeter is @$\begin{align*}m_1\end{align*}@$ .
    ::相反,一个电流计的设计是平行连接电路的,并且具有非常高的抗力。一个电压计测量电压投向抵抗器,而不需要通过电压计进行当前穿透。当一个电压计与抵抗器平行安装时,所有电流都继续通过阻力器,避免电压计的高度抗力。然而,我们知道,所有阻力计的电压下降是相同的,因此将电压计平行连接起来,使其能够准确测量电压投出。在绘图中,电压计是@$\begin{align_1\end_align}@$。

    A galvanometer is a device that uses the generated by a flowing electric current to push a needle. When placed in parallel with a resistor, it can act as an ammeter and be used to measure the amount of current flowing through a circuit. When placed in series with a resistor, it can act as a voltmeter and measure the voltage across the device. Launch the Galvanometer simulation below to learn more:
    ::变速计是一种用流动电流产生的电流生成的装置来推针。 当与抗体平行放置时, 它可以作为一米计, 用来测量电流通过电路的流量。 当与抗体连成序列时, 它可以作为伏度计, 测量整个装置的电压。 启动下面的加瓦计模拟以了解更多 :

    Summary
    ::摘要

    • Ammeters measure the current through a resistor.
      ::通过抵抗器测量水流的仪表。
    • Ammeters have low resistances and are placed in the circuit in series.
      ::仪表有低抗药性,并被分系列置于电路中。
    • Voltmeters measure the voltage drop across a resistor.
      ::伏特计测量电压跌过抵抗器。
    • Voltmeters have high resistances and are placed in the circuit in parallel.
      ::伏特计具有高抗药性,并平行置于电路中。

    Review
    ::回顾

    Four numbered positions in a circuit diagram for placing ammeters and voltmeters.

     

    1. In the sketch at above, there are four positions available for the placement of meters. Which position(s) would be appropriate for placement of an ammeter?
      1. 1
      2. 3
      3. 4
      4. All of them.
        ::全部都是这样
      5. None of them.
        ::没有一个。

      ::在上文的草图中,有4个位置可供放置仪表,哪些位置适合放置仪表? 1,3,4,4, 全部,无。
    2. Which position(s) would be appropriate for placement of a voltmeter?
      1. 1
      2. 2
      3. 3
      4. All of them.
        ::全部都是这样
      5. None of them.
        ::没有一个。

      ::哪个位置适合放置电压计? 1,2,3,4,3,3,4,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
    3. Which position could hold an ammeter that would read the total current through the circuit?
      1. 1
      2. 2
      3. 3
      4. 4
      5. None of them.
        ::没有一个。

      ::哪个位置能保持一个能通过电路读取电流总量的仪表? 12 3 4
    4. Which position could hold a voltmeter that would read the total voltage drop through the circuit?
      1. 1
      2. 2
      3. 3 or 4
        ::3 或 4
      4. All of them.
        ::全部都是这样
      5. None of them.
        ::没有一个。

      ::哪个位置的电压计能读出电路通电的电压? 12 3 或 4 全部 全部 全部 全部

    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. What happens when the ammeter is connected in parallel with the lamp?
      ::当计时器与灯平行连接时会怎样?
    2. Why do the problems occur when the narrator places the ammeter in parallel with the lamp?
      ::为什么问题会发生在 旁白者把弹道表与灯平行的时候?