16.5 Ohm法
Section outline
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The bands of color on a resistor are a code that indicates the magnitude of the of the resistor. There are four color bands identified by letter: A, B, C, and D, with a gap between the C and D bands so that you know which end is A. This particular resistor has a green A band, blue B band, red C band, and red D band, but the bands can be different colors on different resistors. Based on the colors of the bands, it is possible to identify the type of resistor. the A and B bands represent significant digits ; green is 5 and blue is 6. The C band indicates the multiplier, and yellow indicates 10 4 . These three together indicate that this particular resistor is a 560 ,000 Ohm (560 kΩ) resistor. Finally, the D band indicates the tolerance, in this case 2%, as shown by the red band. These terms will be explained over the course of this lesson.
::抵抗者身上的颜色带是一个显示抵抗者大小的代码。 有四个字母标明的颜色带: A、 B、 C和 D, C和 D 之间有差距, 以便您知道哪个是 A 。 这个特定的抵抗者有一个绿色 A 带、 蓝色 B 带、 红色 C 带和 红色 D 带, 但乐队可以是 不同 抵抗者身上的不同颜色 。 根据频带的颜色, 可以确定抵抗者的类型 。 A 和 B 带代表重要数字 ; 绿色 5 和 蓝色 6 。 C 带表示乘数, 黄色 104 表示 104 。 这三组表示这个特定的抵抗者是 560 000 mm (560 k ) 抵抗者。 最后, D 带表示 2% 的容忍度, 如 红 带 所示 。 这些术语将在课程中解释 。Resistance and Ohm’s Law
::抵抗和奥姆法When a potential difference is placed across a metal wire, a large current will flow through the wire. If the same potential difference is placed across a glass rod, almost no current will flow. The property that determines how much current will flow is called the resistance. Resistance is measured by finding the ratio of potential difference, @$\begin{align*}V\end{align*}@$ , to current flow, @$\begin{align*}I\end{align*}@$ .
::当在金属线上放置潜在差异时, 大的电流会通过电线流动。 如果在玻璃杆上放置同样的潜在差异, 几乎不会流。 决定流流多少的属性被称为抵抗。 抵抗是通过找到潜在差异的比例来衡量的, @$\ begin{ align}}V\end{ leign} $, 与当前流量的比例, @ $\ begin{ align}I\end{ laign} 。@$$\begin{align*}R=\frac{V}{I}\end{align*}@$$
::@ $\ begin{ ALIGIN} $} $\ begin{ leign} R { rac{ VI} end{ align} $( 美元) 。When given in the form @$\begin{align*}V = IR\end{align*}@$ , this formula is known as Ohm's Law , after the man that discovered the relationship. The units of resistance can be determined using the units of the other terms in the equation, namely that the potential difference is in volts (J/C) and current in amperes (C/s):
::当以 @ $\ begin{ align@ V = IR\ end{ align}$ 的形式给出时, 此公式被称为“ Ohm's Law ” , 代号为“ Ohm's Law ” , 代号为“ 发现关系的人” 。 抵抗单位可以使用方程式中其他条件的单位来确定, 即潜在差异在伏特( J/ C) 和阿美佩尔( C/ s) 中:@$$\begin{align*}R=\frac{\text{volts}}{\text{amperes}}=\frac{\text{joules/coulomb}}{\text{coulombs/second}}=\frac{\text{joules} \cdot \text{seconds}}{\text{coulombs}^2}=ohms\end{align*}@$$
::@ $\ begin{ legin} r\\ frac\ text{ text{ amperes{ frace{ prooles} joules/ coulomb} text{ coulombs/ second\ frac\ text{ joules} \ cdott\ text{ seconds{ text} coulombs} 2\\ ohms\end{ end{ leign$} 等值{ 等值} $ @ 等值{ 等值}The units for resistance have been given the name ohms and the abbreviation is the Greek letter omega, Ω. 1.00 Ω is the resistance that will allow 1.00 ampere of current to flow through the resistor when the potential difference is 1.00 volt . Most conductors have a constant resistance regardless of the potential difference; these are said to obey Ohm's Law.
::抵抗单位被命名为ohms,缩略语是希腊字母 omega, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\可以\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\可以\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\There are two ways to control the current in a . Since the current is directly proportional to the potential difference and inversely proportional to the resistance, you can increase the current in a circuit by increasing the potential or by decreasing the resistance.
::控制电流有两种方法。由于电流与潜在差异直接成正比,与阻力反比,您可以在电路中增加电流,增加潜力或减少阻力。Example
::示例示例示例示例A 50.0 V battery maintains current through a 20.0 Ω resistor. What is the current through the resistor?
::50.0 V 电池通过20. 0 °° 的阻力保持电流。 阻力器的电流是什么?@$\begin{align*}I=\frac{V}{R}=\frac{50.0 \ V}{20.0 \ \Omega}=2.50 \ amps\end{align*}@$
::@ $\ begin{ legign} I\\ frac{ VRfrac} 50.0\ V20.0\\\ \ \ Omega\\ 2. 50\ amps\ end{ legn} $Launch the PLIX Interactive below to explore how affects the current in a circuit:
::启动下面的 PLIX 互动, 探索电路电流如何影响 :Further Reading
::继续阅读Summary
::摘要-
Resistance is the property that determines the amount of current flow through a particular material.
::抵抗是确定通过特定材料流动量的财产。 -
@$\begin{align*}V = IR\end{align*}@$
is known as Ohm’s Law.
::@$\ begin{align}V = IR\end{align}$ 被称为 Ohm 法 。 -
The unit for resistance is the ohm, and it has the abbreviation Ω.
::抵抗的单位是ohm, 它有缩写_。
Review
::回顾-
If the potential stays the same and the resistance decreases, what happens to the current?
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increase
::增加 -
decrease
::减少 -
stay the same
::保持原样
::如果潜在潜力保持不变,抵抗力减少,那么当前情况如何? 增加的减少保持不变。 -
increase
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If the resistance stays the same and the potential increases, what happens to the current?
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increase
::增加 -
decrease
::减少 -
stay the same
::保持原样
::如果阻力保持不变,而潜在增加的可能性增加,当下会发生什么情况? 增加的减少保持不变。 -
increase
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How much current can be pushed through a 30.0 Ω resistor by a 12.0 V battery?
::有多少电流能通过 30.0 的抗体 推到12.0V 电池? -
What voltage is required to push 4.00 A of current through a 32.0 Ω resistor?
::需要什么样的电压才能将4.00 A电流通过32.0 的阻力器? -
If a 6.00 volt battery will produce 0.300 A of current in a circuit, what is the resistance in the circuit?
::如果6.00伏电池在电路中产生0.300A电流,电路的阻力是什么?
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 。-
What happens to current flow when voltage is increased?
::当电压增加时,目前的流量会怎样? -
What happens to current flow when resistance is increased?
::当抗药性增加时,当前的流动会怎样?
