1. Module 4

1.16. Lesson 3

Lesson 3

Module 4—Magnetic and Electric Fields in Nature and Technology

 

Lesson 3—Electromagnetic Induction

 

Get Focused

 

In Lesson 2 you learned that a charged particle, such as an electron, is deflected by an external magnetic field when it travels perpendicularly to that field. Suppose the electrons are “contained” within a conductor, such as a copper wire. If a copper wire is placed in an external magnetic field such that the electrons within it travel perpendicular to the field, will a magnetic force act on the electrons pushing them along the copper wire?


To see how this would work, view the DC Generator animation.

 

Would such a process work in reverse? That is, can you create a force on a conductor by forcing a current through it? Is this how it is used by an electric motor? What is the difference between an electric motor and a generator?

 

Watch and Listen

 

Questions relating to magnetic and electric fields gained new significance after Ørsted discovered the magnetic field surrounding a current-carrying conductor. The work of Michael Faraday would build on these discoveries and lead to the invention of the world’s first electric motor based on an understanding of electromagnetic induction. Watch the video Faraday’s Discovery of Electromagnetic Induction to see an overview of Michael Faraday’s work, including a re-creation of the first electric motor.

 

Faraday’s work was based on the following fundamental question:

  • If an electric current produces a magnetic field, could a magnetic field be used to produce an electric current?

In Lesson 3 you will explore electromagnetic induction.

 

In this lesson you will answer the following essential questions:

  • What is the nature of the magnetic force acting on a current-carrying conductor in an external magnetic field?

  • How are magnetic forces used in a direct current motor?

  • How is a current produced by an electric generator?

Module 4: Lesson 3 Assignment

 

Your teacher-marked Module 4: Lesson 3 Assignment requires you to submit a response to the following questions:

  • Assignment—A 1, A 2, A 3, and A 4
  • Lab—LAB 1, LAB 2, LAB 3, LAB 4, LAB 5, and LAB 6
  • Discuss—D 3

The other questions in this lesson are not marked by the teacher; however, you should still answer these questions. The Self-Check and Try This questions are placed in this lesson to help you review important information and build key concepts that may be applied in future lessons.

 

After a discussion with your teacher, you must decide what to do with the questions that are not part of your assignment. You should record the answers to all the questions in this lesson and place those answers in your course folder.