"Electric Motor" Electricity and Magnetism PPT Courseware 4

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"Electric Motor" Electricity and Magnetism PPT Courseware 4

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1. The basic property of a magnetic field is that it acts ( ) on the magnets placed in it, and the interaction between magnets occurs through ( ).

2. Place a wire parallel to a stationary small magnetic needle. When the wire is energized, a small magnetic needle ( ) is found, indicating that there is a current ( ) around it.

learning target

1. Know that a magnetic field exerts a force on a current-carrying conductor

2. Know that the direction of force exerted by a current-carrying conductor in a magnetic field is related to the direction of the current and the direction of the magnetic field.

3. Understand the structure and working principle of DC motor.

4. Know the function of commutator. Know the conversion of energy when the motor is working.

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

1. The effect of magnetic field on current

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

Experiments show:

1. A current-carrying wire is acted upon by a force in a magnetic field.

2. What does the direction of the force experienced by a current-carrying conductor in a magnetic field depend on?

Experiments show:

2. The direction in which a current-carrying wire receives a force in a magnetic field is related to the direction of the current and the direction of the magnetic field.

(When only the direction of the current is changed or only the direction of the magnetic field is changed, the direction of the magnetic field force on the current-carrying conductor changes.)

3. The process in which a current-carrying conductor is subjected to force in a magnetic field is the process of converting electrical energy into mechanical energy.

Electric motors in life

1. Classification:

DC motors (electric toys, tape recorders and other small appliances)

AC motors (electric fans, washing machines and other household appliances)

2. Energy conversion:

An electric motor is a power machine that converts electrical energy into mechanical energy

3. Advantages of electric motors:

It has simple structure, convenient control, small size and high efficiency.

speaker

1. Definition: A speaker is a device that converts electrical signals into acoustic signals.

2.Construction:

It is mainly composed of fixed permanent magnets, coils and conical paper cones.

3. How the speaker works:

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.

Classroom training

1. The direction of the magnetic field's force on the current is related to the ____ direction and the ____ direction.

2. The working principle of the electric motor is ___________. The electric motor converts __ energy into ____ energy during the working process.

3. The simplest commutator for a DC motor is __________. Its function is to change the direction of the current passing through ____ so that the motor can rotate continuously.

4. Every time the coil of a DC motor rotates once, the direction of the current in the coil changes _ times. The equilibrium position is: _______________.

5. To change the rotation direction of a DC motor, the method that should be adopted is ( )

A. Enhance the magnetism of magnetic poles

B． Increase the power current

C. Change the direction of current in a coil

D. Reverse the poles of the magnet

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: 2024-09-09

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

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