Section outline

  • General

    Collapse all Expand all

  • 《 Ohm's 律法》

    Water spraying from a garden hose, illustrating concepts related to flow and electricity.

    Look at the water spraying out of this garden hose. You have to be careful using water around power tools and electric outlets because water can conduct an electric current . But in some ways, water flowing through a hose is like electric current flowing through a wire.
    ::看看这根花园水管的喷水情况。你必须小心使用电动工具和电源插口周围的水,因为水可以产生电流。 但在某些方面,水通过水管流就像电流通过电线流。

    Introducing Ohm’s Law
    ::介绍奥姆法

    For electric current to flow through a wire, there must be a source of voltage . Voltage is a difference in electric . As you might have guessed, greater voltage results in more current. As electric current flows through matter, particles of matter resist the moving charges. This is called , and greater resistance results in less current. These relationships between electric current, voltage, and resistance were first demonstrated in the early 1800s by a German scientist named Georg Ohm, so they are referred to as . Ohm’s law can be represented by the following equation.
    ::为了让电流通过电线流动,必须有一个电压源。电压是电的差别。正如你可能猜想的那样,电压越大,电压越大,电压越大,电流越流,物质粒子就越能阻力。这被称为“电流 ” , 阻力越强,电阻力就越小。 电流、电压和阻力之间的关系最早在1800年代初由德国科学家Georg Ohm演示,因此被称为“电压 ” 。 Ohm的法律可以用下面的方程式来代表。

    Current(amps) = V o l t a g e ( v o l t s ) R e s i s t a n c e ( o h m s )

    Understanding Ohm’s Law
    ::理解奥姆法

    Ohm’s law may be easier to understand with an analogy. Current flowing through a wire is like water flowing through a hose. Increasing voltage with a higher-volt battery increases the current. This is like opening the tap wider so more water flows through the hose. Increasing resistance reduces the current. This is like stepping on the hose so less water can flow through it.
    ::Ohm法则可能比较容易理解。 电线流流就像水管流。 用高压电池增加电压会增加电流。 这就像开水龙头,通过水龙头增加水流。 抗力增强会减少电流。 这就像踩水龙头,这样水龙头的流量就更少了。

    Using Ohm’s Law to Calculate Current
    ::使用 Ohm 法则计算当前

    You can use the equation for current (above) to calculate the amount of current flowing through a when the voltage and resistance are known. Consider an electric wire that is connected to a 12-volt battery. If the wire has a resistance of 2 ohms, how much current is flowing through the wire?
    ::您可以使用当前( 以上) 的方程式来计算电流在电压和阻力已知时通过电流的流量。 想象一下连接到 12伏电池的电线。 如果电线的阻力为 2 ohms, 电流的流量是多少 ?

    Current = 12 v o l t s 2 o h m s = 6 amps

    Q: If a 120-volt voltage source is connected to a wire with 10 ohms of resistance, how much current is flowing through the wire?
    ::问题:如果120伏的电压源连接到有10赫姆抗力的电线上,那么电流通过电线流了多少?

    A: Substitute these values into the equation for current:
    ::A: 将这些数值替换为当前值的方程式:

    Current = 120 v o l t s 10 o h m s = 12 amps

    Explore how Ohm's Law affects the current in a circuit by launching the PLIX Interactive below:
    ::探索奥姆定律如何在电路中影响电流,

    Summary
    ::摘要

    • According to Ohm’s law, greater voltage results in more current and greater resistance results in less current.
      ::根据Ohm的法律,更大的电压导致更时髦的电压,更大的抵抗力导致更时髦的电压。
    • Ohm’s law can be represented by the equation:
      ::Ohm的法律可以用下列等式来代表:

    C u r r e n t   ( a m p s ) = V o l t a g e   ( v o l t s ) R e s i s t a n c e   ( o h m s )
    ::当前 (amps) = 排量 (volts) 恢复 (ohms)

    • This equation can be used to calculate current when voltage and resistance are known.
      ::当知道电压和阻力时,可以使用此方程式计算当前电流 。

    Review
    ::回顾

    1. State Ohm’s law.
      ::州立奥姆法律。
    2. An electric appliance is connected by wires to a 240-volt source of voltage. If the combined resistance of the appliance and wires is 12 ohms, how much current is flowing through the circuit?
      ::电动电器通过电线连接到240伏的电压源。 如果电动电器和电线的阻力加在一起是12 ohms,电流通过电路流量是多少?