Name: resistivity in conductors and insulators
Uploaded: 2023-04-30T12:38:52.000Z
Duration: 1 min 22 s
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K12 Standards

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North Carolina K-12 Science Standard Course of Study

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Physical Science

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Motion and Stability- Forces and Interactions

PS.PSc.6.2

Resistivity

전기 저항은 재료의 고유한 특성으로, 전하의 흐름에 얼마나 효과적으로 저항하는지 설명합니다.
저항률은 전기 전도도의 역수이며 전기장과 전류 밀도로 정의할 수 있습니다. 저항률의 SI 단위는 옴미터입니다.
좋은 도체는 전도성이 높지만 저항이 낮은 반면 좋은 절연체는 전도성이 낮지만 저항률이 높습니다.
온도는 일부 재료의 저항률에 영향을 미칩니다. 많은 재료에서 의존성은 거의 선형이며 ρ는 온도에서의 재료의 저항, α는 재료의 온도 계수, ρ0은 실온에서의 저항률인 선형 방정식을 사용하여 모델링할 수 있습니다.
구리와 같은 일부 물질의 저항률은 온도가 증가함에 따라 증가하고, 탄소와 같은 다른 물질의 저항률은 온도가 증가함에 따라 저항률이 감소합니다.
반도체에서 온도 계수는 음수이며, 이는 온도가 증가함에 따라 저항이 감소한다는 것을 의미합니다.

<ol>
	<li>오픈스택스. (2019). 대학 물리학 Vol. 2. [웹 버전], 페이지 396 - 398. 원본 주소 <a href="https://openstax.org/books/university-physics-volume-2/pages/9-3-resistivity-and-resistance">https://openstax.org/books/university-physics-volume-2/pages/9-3-resistivity-and-resistance</a></li>
</ol>

비저항

도체에 전압을 가하면 전기장이 생성되고, 도체 내부의 전하는 전기장으로 인해 힘을 느끼게 됩니다. 결과로 나타나는 전류 밀도는 전기장과 재료의 특성에 따라 달라집니다. 주어진 온도에서 금속을 포함한 일부 재료에서 전류 밀도는 대략 전기장에 비례합니다. 이러한 경우 전류 밀도는 다음과 같이 모델링될 수 있습니다.

<img alt="Equation1" src="/files/ftp_upload/13746/13746_Equation_1.svg" style="text-align: center; height: 16px;" />

여기서 σ은 전기 전도도이며 (Ω·m)−1으로 표시됩니다. 전기 전도성은 열 전도성과 유사하며 전기를 전도하거나 전달하는 재료의 능력을 측정한 것입니다. 도체는 절연체보다 전기 전도성이 더 높습니다. 전도도는 재료의 고유한 특성입니다. 재료의 또 다른 고유 특성은 저항률, 즉 전기 저항률입니다. 물질의 저항률은 물질이 전류 흐름에 얼마나 강하게 저항하는지를 나타내는 척도입니다. 저항률은 전기 전도도의 역수로 나타낼 수 있으며 그리스 문자 로(ρ)로 표시됩니다. SI 단위의 저항률 단위는 옴미터입니다. 저항률은 전기장과 전류 밀도의 비율로 정의할 수도 있습니다. 저항률이 높을수록 주어진 전류 밀도를 생성하는 데 필요한 필드가 커집니다. 저항률이 낮을수록 주어진 전기장에 의해 생성되는 전류 밀도가 커집니다. 표 1에 나타난 바와 같이, good  도체는 전도성이 높고 저항률이 낮은 반면, 좋은 절연체는 전도성이 낮고 저항률이 높습니다.

표 1: 다양한 재료의 저항률 및 전도도 값이 나열되어 있습니다.

<table style="margin-left: auto; margin-right: auto;">
	<tbody style="border: 1px solid black;">
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">재료</td>
			<td style="color: black; border: 1px solid black; text-align: center;">전도율, σ 
			( Ω · m)−1</td>
			<td style="color: black; border: 1px solid black; text-align: center;">저항률, ρ 
			( Ω · m)</td>
			<td style="color: black; border: 1px solid black; text-align: center;">온도 
			계수, α (°C)−1</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">은색</td>
			<td style="color: black; border: 1px solid black; text-align: center;">6.29 × 107</td>
			<td style="color: black; border: 1px solid black; text-align: center;">1.59 × 10−8</td>
			<td style="color: black; border: 1px solid black; text-align: center;">0.0038</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">구리</td>
			<td style="color: black; border: 1px solid black; text-align: center;">5.95 × 107</td>
			<td style="color: black; border: 1px solid black; text-align: center;">1.68 × 10−8</td>
			<td style="color: black; border: 1px solid black; text-align: center;">0.0039</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">금색</td>
			<td style="color: black; border: 1px solid black; text-align: center;">4.10 × 107</td>
			<td style="color: black; border: 1px solid black; text-align: center;">2.44 × 10−8</td>
			<td style="color: black; border: 1px solid black; text-align: center;">0.0034</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">알루미늄</td>
			<td style="color: black; border: 1px solid black; text-align: center;">3.77 × 107</td>
			<td style="color: black; border: 1px solid black; text-align: center;">2.65 × 10−8</td>
			<td style="color: black; border: 1px solid black; text-align: center;">0.0039</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">텅스텐</td>
			<td style="color: black; border: 1px solid black; text-align: center;">1.79 × 107</td>
			<td style="color: black; border: 1px solid black; text-align: center;">5.60 × 10−8</td>
			<td style="color: black; border: 1px solid black; text-align: center;">0.0045</td>
		</tr>
		<tr>
			<td style="color: black; border: 1px solid black; text-align: center;">카본(순수)</td>
			<td style="color: black; border: 1px solid black; text-align: center;">2.86 × 10−6 </td>
			<td style="color: black; border: 1px solid black; text-align: center;"></td>
			<td style="color: black; border: 1px solid black; text-align: center;"></td>
		</tr>
	</tbody>
</table>

도체에 전압이 가해지면 전기장이 발생하고 도체의 전하는 전기장으로 인한 힘을 느낍니다. 그만큼 ...

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Unit 1

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Current and Resistance

전류와 저항

KEY TERMS AND CONCEPTS

주요 용어 및 개념

resistivity in conductors and insulators

Resistivity describes how much a material opposes electric current. When a voltage is applied to a conductor, an electric field forms. The charges in the conductor feel that force, and a current density develops. In some materials, including metals at a given temperature, the current density is approximately proportional to the electric field.

In those cases, current density can be modeled with conductivity, written as sigma. Electrical conductivity is measured in (ohm·m)^−1. It tells how well a material can conduct electricity. This idea is similar to thermal conductivity, which describes how well a material carries heat. Conductors have higher electrical conductivity than insulators, and conductivity is an intrinsic property of the material.

Resistivity, written as rho, is another intrinsic property. It is the reciprocal of electrical conductivity. In SI units, resistivity is measured in ohm-meter. It can also be defined as the ratio of electric field to current density. A higher resistivity means a larger electric field is needed to produce a given current density. A lower resistivity means the same electric field produces a larger current density.

The transcript also compares common materials. Good conductors have high conductivity and low resistivity. Good insulators have low conductivity and high resistivity. Examples of good conductors include silver, copper, gold, aluminum, and tungsten. Pure carbon has much lower conductivity than these metals. Silicon falls between conductor and insulator values, while amber, glass, and Lucite show very high resistivity and very low conductivity.

Resistivity in Conductors and Insulators

electrical current

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resistivity

Resistivity describes how much a material opposes electric current. When a voltage is applied to a conductor, an electric field forms. The charges in the conductor feel that force, and a current density develops. In some materials, including metals at a given temperature, the current density is approximately proportional to the electric field. In those cases, current density can be modeled with conductivity, written as sigma. Electrical conductivity is measured in (ohm·m)^−1. It tells how well...

resistance

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Electrical resistance describes how much a conductor opposes the flow of current. It is represented by R. When current passes through a conductor, heat is also produced. Resistance is tied to the material’s resistivity, which is a property of the material used to make an electrical component. Resistance is different from resistivity. Resistivity belongs to the material itself, while resistance belongs to the finished component. To study this relationship, consider a wire with length L,...

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key terms and concepts

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Resistivity in Conductors and Insulators | JoVE K12

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Resistivity in Conductors and Insulators

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