"Conductivity and Resistance of Matter" PPT download

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"Conductivity and Resistance of Matter" PPT download

Part One Content: Life Examples

What objects in life easily conduct electricity? Which ones don’t conduct electricity easily?

Coins, plastic ruler, glass pieces, pencil lead, salt water, chalk, purified water

How to design an experiment?

1. Judgment criteria

2. Experimental instruments

3. Design circuit diagram

4. Experimental process

5.Experimental results

Conductivity and resistance of matter PPT, part 2: conductors and insulators

1. Objects that easily conduct electricity are called conductors.

For example: metal, human body, earth, graphite, salt water...

2. Objects that do not conduct electricity easily are called insulators.

For example: rubber, glass, ceramics, plastics, dry wood, oil, dry air...

Discussion: Can water conduct electricity?

Pure water is non-conductive, while natural ordinary water contains a large number of other substances that can conduct electricity. Therefore, pure water is a kind of __________, and natural water is a kind of ________.

Pure water is non-conductive, but because there are a large number of other substances dissolved in natural water, the water used in daily life is generally conductive.

Transformation between conductors and insulators

Glass at room temperature is an insulator; when it is heated red, it becomes a conductor.

Pure water is an insulator; water containing impurities is often a conductor.

Dry air is an insulator, and moist air under high pressure is a conductor.

Conclusion: There is no absolute boundary between conductors and insulators, and they can transform into each other under certain conditions.

Thoughts and Discussions

Could you please explain from the perspective of electric charge why glass can conduct electricity after it is heated red?

After the glass is heated red, the electrons inside can move freely, so it can conduct electricity.

Conductivity and resistance of matter PPT, Part 3: Resistance

1. Different materials have strong or weak electrical conductivity. In order to compare the electrical conductivity of various materials, ______ is introduced.

2. Resistance is the resistance of a conductor to electric current.

3. Insulators have very high resistance, while conductors have relatively small resistance.

4. Resistance is represented by the letter _______.

Unit of resistance: _______abbreviated as_______; symbol:_______.

Units larger than ohms include: kiloohms (kΩ), megaohms (MΩ)

Conversion relationship: 1 megohm = 103 kilohm = 106 ohm

Conductivity and resistance of matter PPT, Part 4 content: Practice:

1. Which of the following objects are conductors ( )

A. Earth, rubber B. Pure water, carbon rod

C. Human body, metal D. Oil, aqueous solution

2. The reason why insulators are not easy to conduct electricity is because of the inside ( )

A. No charged particles B. Almost no electrons

C. There are very few free charges. D. There are a lot of free electrons.

test you

1. When you find someone getting an electric shock, what should you do to separate the wires?

2. In thunderstorm weather, is it better to hold the umbrella with your hand on the handle or the umbrella pole?

3. Do all conductors have the same conductivity?

How to design experimental verification?

Keywords: Zhejiang Education Edition eighth grade science PPT courseware free download, conductivity and resistance of matter PPT download, .PPT format;

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"Conductivity and Resistance of Matter" PPT courseware:

The first part of the PPT courseware "Conductivity and Resistance of Matter": Exploration and Application I will explore. Please put iron nails, plastic rulers, glass, pencil lead (carbon rod), salt water, matches, mineral water, etc. or choose one yourself Items of interest, connected to the circuit, detected...

"Conductivity and Resistance of Matter" PPT:

"Conductivity and Resistance of Materials" PPT Part One: Classroom Experiments Try it: How to detect the conductivity of materials Metal sheets, plastic rulers, glass rods, pencil leads (carbon rods), chalk, coins and other substances. Which objects do you think conduct electricity easily? What things...

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Update Time: 2024-09-27

This template belongs to science courseware Zhejiang Education Edition Eighth Grade Science Volume 1 industry PPT template

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