"Electric Magnetism" PPT

Description

"Electric Magnetism" PPT

Part One: Oersted's Experiment

In 1820, Danish physicist Oersted finally experimentally confirmed the existence of a magnetic field around an energized conductor. This major discovery shocked the scientific community and brought electromagnetism into a new development period.

The magnetic field of the current is related to the direction of the current. If the direction of the current is changed, the direction of the magnetic field will also change.

Exploration 2 How is the magnetic field distributed around a straight current-carrying wire?

Pierce a small hole in the plexiglass plate, pass a straight wire vertically through the hole, and evenly sprinkle some iron filings on the glass plate. After energizing the straight wire, tap the glass plate lightly to observe the distribution of iron filings.

Concentric circles with each point on a straight conductor as the center

The plane of these concentric circles is perpendicular to the straight wire

The closer you are to a straight wire, the stronger the magnetic field;

The further away from the straight wire, the weaker the magnetic field

Conclusion: The closer to a straight wire, the stronger the magnetism. Magnetic field lines are concentric circles with each point on the conductor as the center, and they are all on a plane perpendicular to the conductor.

Electromagnetic PPT, Part 2: Magnetic field of energized solenoid

experiment

1. After winding the wire into a solenoid, attract the pin or get close to the small magnetic needle and observe the phenomenon.

2. Energize the solenoid, attract the pin or get close to the small magnetic needle, and observe the phenomenon.

Conclusion; there is also a magnetic field around the energized solenoid

3. Insert an iron nail into the solenoid and attract the pin to observe the phenomenon.

Conclusion: A energized solenoid with an iron core is more magnetic than one without an iron core

Electromagnetic PPT, Part 3: Ampere’s Rule

An energized solenoid is equivalent to a bar magnet, and the relationship between its polarity and current direction is as follows:

Ampere's rule - right-hand spiral rule.

Method and sequence of applying Ampere's rule:

1: Find out the winding direction of the solenoid.

2: Mark the direction of the current in the solenoid.

3: Use Ampere's rule to determine the magnetic pole direction of the solenoid.

(The thumb points to the N magnetic pole direction)

Electromagnetic PPT, Part 4: Classroom Experiment

Experiment: The magnetic strength of a energized solenoid

in conclusion

An energized solenoid with an iron core is more magnetic than an energized solenoid without an iron core.

electromagnet

We call the energized solenoid inserted into the iron core an electromagnet.

The presence or absence of magnetism in electromagnets can be controlled by current

think

Why is the iron core made of iron? And not made of steel? Why is the magnetism greatly enhanced after inserting the iron core?

When the iron core is inserted into the energized solenoid, the iron core is magnetized and a magnetic field is generated. Therefore, there are both the magnetic field generated by the current and the magnetic field generated by the magnet around the energized solenoid, so the magnetic field is greatly enhanced.

Keywords: Zhejiang Education Edition eighth grade science PPT courseware for the second volume free download, electromagnetic PPT download, .PPT format;

For more information about the "Electromagnetism" PPT courseware, please click the "Electromagnetism ppt" tab.

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Update Time: 2024-10-15

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