# Electromagnetics

Electromagnetic energy travels through space in the form of electrical and magnetic waves.

## UNC-TV Media

Videos:

Reporter's Blogs:

Interactive:

## Alignment to NC Essential Standards

• PSc.3.3.5 — Explain the practical application of magnetism.

### Learning Outcomes

Students will describe the relationship between electricity and magnetism in practical applications such as motors and electric guitars.

### Essential Questions

1. Discuss the role of electromagnets in the transformation of electrical energy to mechanical energy in a motor.
2. Describe the process of electromagnetic induction in an electric guitar and amplifier.

## Engage

Follow the attached Electromagnetic Demonstration Instructions to put together an electromagnet for the class.

Discussion Questions:

1. What is the fundamental element of an alternate-current (AC) motor?
2. What do electromagnets cause in an AC motor?

## Explore

Students will watch the NC Science Now Video The Marvelous Music Machine, taking notes on the following discussion questions:

1. How does an acoustic guitar produce sound, and how does the length of the string being played affect that sound?
2. How does the Vo-96 change the physics of the guitar sound?

## Explain

Explain to the class that electric guitars make their sound through electromagnetic induction. Have the class complete the interactive activity Rock and Roll Energy. Afterward, students should answer the following questions:

1. What are electric guitar pickups composed of?
2. Describe the process by which the electric current in the wire around the pickup is created.
3. What is the process described in question two called?
4. How does the amplifier affect the electric signal from the guitar?
5. What happens to the electric energy once it reaches the amplifier?

## Extend

Students will watch the NC Science Now Video The Touchdown Magnet, taking notes on the following discussion questions:

1. Describe the advantages of using magnetic waves to track the football in the video.
2. What is the main difference between the method of electromagnetic energy conversion in the lab experiment described in the video and the way in which energy is converted within the football?
3. Compare and contrast the conversion of energy in the Rock and Roll energy interactive piece and the Touchdown Magnet video. What are the similarities, and what are the differences?

## Evaluate

Divide students into teams, each of which will design a poster board describing the relationship between electricity and magnetism in one of the two following applications (with accompanying resources):