"Electric Motor" Electricity and Magnetism PPT Courseware 2

Description

"Electric Motor" Electricity and Magnetism PPT Courseware 2

We have learned before that the current-carrying wire has a strong effect on the small magnetic needle, so think about it, if the magnetic field in turn has a strong effect on the current-carrying wire?

Think about it, what experiment should be designed to verify it?

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

(1) Conjecture:

A current-carrying wire experiences a force in a magnetic field.

(2) Design experiments:

(3) Experimental operations:

Just now we put a current-carrying wire in a magnetic field and found that it will be acted upon by a force. What if instead of placing a wire, we put the entire coil in the magnetic field?

It can be observed that the coil rotates. Why does the coil rotate instead of moving in a straight line?

Since the current directions on both sides of the wire are different, the forces they receive are also different, just like a frame being twisted by forces in opposite directions, so it can only rotate.

3. Electric motors in life

Motor type:

DC motor AC motor

When the motor is energized, the rotor rotates and electrical energy is converted into mechanical motion energy. Since the power grid supplies alternating current, most of the motors in household appliances such as electric fans and washing machines are AC motors. AC motors also rely on the force exerted by energized conductors in a magnetic field to operate. Small electrical appliances such as electric toys and tape recorders mostly use DC motors.

advantage:

Simple structure, convenient control, small size, high efficiency, large or small power, no pollution

With this advantage, electric motors are widely used in social life. Electric irrigation stations in rural areas and various machine tools in factories have electric motors. Trams and electric locomotives are all means of transportation powered by electric motors. Since electric motors do not pollute the environment like internal combustion engines, the use of electricity as power should be promoted. Research on electric vehicles powered by solar energy or batteries has entered the experimental trial stage. With the development of technology and social progress, the relationship between electric motors and humans will become increasingly close.

summary

1. A current-carrying wire will experience a force in the magnetic field. The direction of the force is related to the direction of the current and the direction of the magnetic field lines.

2. Electric motor

①Principle: The energized coil is forced to rotate in the magnetic field. (oersted)

②Structure: stator, rotor.

③Conversion of energy: electrical energy is converted into mechanical energy.

④Commutator (two semicircular copper rings):

Function: Change the direction of the current in the coil in time so that the force direction of the coil is always the same and the coil can continue to rotate.

⑤Advantages: simple structure, convenient control, small size, high efficiency, large or small power, no pollution

Consolidation exercises

1. A current-carrying conductor in a magnetic field ( )

A. It must be affected by the magnetic force

B． May be affected by magnetic field forces

C. Must not be affected by magnetic field forces

D. None of the above statements are correct

2. To change the direction of the DC motor, you can use ( )

A. Change the direction of the current, keeping everything else unchanged

B. Change the direction of the magnetic field, keeping everything else unchanged

C. Increase the current intensity

D. Change the direction of current and magnetic field at the same time

3. Which of the following statements is correct ( )

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

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

C. DC motors use the rotation of coils to generate current.

D. Changing the direction of the current in the coil can change the speed of the motor coil rotation

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: 2024-10-27

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

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