How Is a Radio Wave Emitted?

Learning Resource Type

Classroom Resource

Subject Area

Science

Grade(s)

8

Overview

The sound produced for a radio broadcast may take three different forms and travel dozens of miles before it comes out of your loudspeaker. This illustrated essay from A Science Odyssey Web site explains the conversion of electrical signals to radio waves.

Science (2015) Grade(s): 8

SC15.8.19

Integrate qualitative information to explain that common communication devices (e.g., cellular telephones, radios, remote controls, Wi-Fi components, global positioning systems [GPS], wireless technology components) use electromagnetic waves to encode and transmit information.

UP:SC15.8.19

Vocabulary

  • Qualitative
  • Information
  • Communication devices (e.g., cellular phone, Global Positioning System (GPS), remote control, Wi-Fi, etc.)
  • Electromagnetic waves
  • Energy
  • Energy wave
  • Electric field
  • Magnet
  • Magnetic field
  • Mechanical wave
  • Vacuum
  • Frequency
  • Wavelength
  • Crest
  • Medium
  • Amplitude
  • Displacement
  • Rest position
  • Encode
  • Transmit

Knowledge

Students know:
  • Electromagnetic waves are a form of energy waves that have both an electric and magnetic field. Electromagnetic waves are different from mechanical waves in that they can transmit energy and travel through a vacuum.
  • The different types of electromagnetic waves have different uses and functions in our everyday lives.
  • Electromagnetic waves differ from each other in wavelength, frequency, and energy, and are classified accordingly. Wavelength is the distance between one wave crest to the next.
  • Frequency refers to how often the particles of the medium vibrate when a wave passes through the medium
  • The amount of energy carried by a wave is related to the amplitude of the wave. A high energy wave is characterized by a high amplitude; a low energy wave is characterized by a low amplitude. The amplitude of a wave refers to the maximum amount of displacement of a particle on the medium from its rest position.
  • Electromagnetic waves can be used to encode information.
  • Electromagnetic waves can be used to transmit information.
  • Examples of common communication devices may include cellular telephones, radios, remote controls, Wi-Fi components, global positioning systems (GPS), and wireless technology components.

Skills

Students are able to:
  • Gather evidence sufficient to explain a phenomenon that includes the idea that using waves to carry digital signals is a more reliable way to encode and transmit information than using waves to carry analog signals.
  • Combine the relevant information (from multiple sources) to articulate the explanation.

Understanding

Students understand that:
  • Common communication devices use electromagnetic waves to encode and transmit information.

Scientific and Engineering Practices

Obtaining, Evaluating, and Communicating Information

Crosscutting Concepts

Structure and Function

CR Resource Type

Informational Material

Resource Provider

PBS

License Type

Custom

Accessibility

Text Resources: Content is organized under headings and subheadings
ALSDE LOGO