"Electric Motor" Electricity and Magnetism PPT Courseware

Description

"Electric Motor" Electricity and Magnetism PPT Courseware

1: Observe and think

1. Where are electric motors used in life and production?

2. If you energize the motor, it will rotate. Why? That is, what is the working principle of an electric motor?

Want to discuss

What exists around a magnet? magnetic field

What exists around a straight conductor carrying electricity? magnetic field

Magnets interact with each other through magnetic fields

Will the current-carrying wire also be affected by the magnetic field?

1. The effect of magnetic field on current-carrying wires

Demonstration experiment

① Close the switch and observe the movement of the aluminum straight conductor.

② Change the direction of current or change the direction of magnetic field.

Experimental phenomena

When the switch is closed, the conductor that was originally stationary in the magnetic field moves.

The direction of the current does not change, but the direction of the magnetic field changes, and the direction of motion of the conductor in the magnetic field changes.

The direction of the magnetic field does not change, but if the direction of the current changes, the direction of motion of the conductor in the magnetic field also changes.

Conclusion: The effect of magnetic field on electric current

1. The current-carrying wire is affected by ___ in the magnetic field

2. The direction of force exerted on a current-carrying wire in a magnetic field is related to __________

3. The direction of force exerted on a current-carrying wire in a magnetic field is related to _________

4. Only change the direction of the force on the ___________ or ___________ current conductor _________, if _________ changes the direction of the current and the direction of the magnetic field, the direction of the force will be ________

Think about it: What would happen if instead of a current-carrying wire, a current-carrying coil was placed in a magnetic field?

2. Basic structure of electric motor

1. An electric motor consists of two parts: a coil that can rotate, also called a rotor. A fixed magnet is also called a stator.

think about it

If in the second half of the coil's rotation, instead of stopping the power supply to the coil, we try to change the direction of the current in the second half of the rotation so that the coil also gets power in the second half of the rotation, wouldn't the coil rotate more smoothly?

2. commutator

The commutator allows the current in the coil to change every half cycle.

exercise

1. Fill in the blanks

1. The electric motor is mainly composed of _______ and _______. It is made by using the principle that the _____ coil is forced to rotate in _______.

2. If only the direction of the magnetic field or the direction of the current is changed, the force on the current-carrying wire will be __________; if the direction of the current and the direction of the magnetic field are changed at the same time, the force on the current-carrying wire will be ___________.

3. When a current-carrying conductor is forced to move in a magnetic field ( )

A. Electrical energy is consumed and mechanical energy is produced

B. Mechanical energy is consumed and electrical energy is produced

C. Mechanical energy is consumed and internal energy is generated

D． Chemical energy is consumed and electrical energy is produced

The principle and structure of loudspeakers

A speaker is a device that converts electrical signals into acoustic signals. It is mainly composed of fixed permanent magnets, coils and cone-shaped paper cones.

How do speakers produce sound?

When a current as shown in the figure passes through the coil, the coil is attracted by the magnet and moves to the left. When a current in the opposite direction passes through the coil, the coil is repelled by the magnet and moves to the right. Since the current passing through the coil is an alternating current, its direction is constantly changing, and the coil continues to vibrate back and forth, driving the paper cone to vibrate back and forth, so the speaker produces sound.

Keywords: Electricity and magnetism teaching courseware, Electric motor teaching courseware, New People's Education Edition ninth-grade physics PPT courseware, Ninth-grade physics slide courseware download, Electricity and magnetism PPT courseware download, Electric motor PPT courseware download, .ppt format

For more information about the PPT courseware "Electrical Motors, Electricity and Magnetism", please click on the Electric Motors ppt Electricity and Magnetism ppt tab.

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Update Time: 2024-07-04

This template belongs to Physics courseware People's Education Edition Ninth Grade Physics Complete Book industry PPT template

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