Basic wave vocabulary, algebra and scientific graph reading are helpful. A notebook supports diagrams and comparisons. The classroom contains educational videos, with no supervised experiment, full physics assessment, school credit or professional qualification included.
Optional preparation: High School Physics: Free Course.
About this course
Explore the recorded foundations of electromagnetic radiation in this free Khan Academy physics course. All seven source videos are retained, covering waves, refraction, diffraction and interference, photoelectric and photovoltaic effects, atomic spectra, blackbody radiation and the greenhouse-effect explanation. The course provides a focused conceptual study unit.
Course at a glance
| Provider / Teaching team | Khan Academy |
|---|---|
| Platform | YouTube · Khan Academy |
| Access | Free Video |
| Level | Intermediate |
| Language | English |
| Videos | 7 |
| Video duration | 1h 40m · allow extra time for practice |
| Format | Self-paced recorded training |
| Certificate | Not included with video viewing |
What you’ll learn
- Connect the electromagnetic-wave lesson with later light-interaction topics.
- Compare refraction, diffraction and interference in the recorded explanations.
- Explore the source photoelectric, photovoltaic and atomic-spectra examples.
- Review the blackbody and greenhouse-effect teaching discussions.
Skills you’ll gain
- Electromagnetic waves
- Light interactions
- Wave comparison
- Atomic-spectra concepts
- Radiation study
- Scientific reasoning
Course Overview
The first recording establishes electromagnetic waves before the course introduces several ways light and matter interact. Refraction and the diffraction-and-interference lesson provide contrasting wave-related examples. The photoelectric and photovoltaic recording then adds a different type of explanation, followed by atomic spectra. Blackbody radiation and the greenhouse-effect lesson complete the seven-video source sequence. Every recording remains available. This is a focused conceptual course rather than a complete electricity-and-magnetism syllabus or a practical optical-laboratory program. Its useful outcome is the ability to distinguish the questions addressed by different radiation concepts and connect each with the source example that explains it.
How to study the course
- Begin with electromagnetic waves and refraction. Keep the properties of a wave distinct from the behavior discussed at an interaction.
- Study diffraction, interference, photoelectric and photovoltaic effects. Compare what each explanation is trying to account for rather than combining all light phenomena into one rule.
- Complete atomic spectra, blackbody radiation and the greenhouse-effect recording. Build a concept map and revisit the lesson for a link you cannot explain clearly.
Use the searchable classroom lesson list to revisit a specific explanation. Pause after a useful demonstration, reproduce a small example and explain the result in your own words. Keep a short note of what worked, what changed and what you still need to understand before moving on.
Who is this for?
This course suits students with an introductory physics background and curious learners studying the behavior of light and radiation. It is also useful as a short conceptual supplement to a formal science class.
Before you start
Basic wave vocabulary, algebra and scientific graph reading are helpful. A notebook supports diagrams and comparisons. The classroom contains educational videos, with no supervised experiment, full physics assessment, school credit or professional qualification included.
Put the lessons into practice
Create a comparison sheet for several phenomena covered by the course. Use columns for the question being explained, the relevant wave or matter concept and a source example. Draw a simple study sketch for one interaction and explain what the sketch leaves out. Then connect an atomic-spectra or blackbody lesson with the broader course map. Keep the explanation conceptual and check every important relationship against its recording. Finish by writing a short distinction between two phenomena you previously found easy to confuse.
This optional activity is provided by WikiFree for independent practice. It is not a graded assignment from the instructor. Keep your working notes, check the result against the task you defined and return to the relevant lesson when an assumption or technique is unclear.
Certificate / Assessment
Watching the public videos and using WikiFree progress tracking does not award a certificate, exam voucher, academic credit or instructor assessment.
Use your practice output to review what you can now explain and repeat independently. Completion tracking records your study progress; it does not replace an assessed qualification or professional experience.
Related courses for your next step
- Review a lower-level optionHigh School Physics: Free Course
Focus: Physics models · Motion analysis
Beginner - Review a lower-level optionMiddle School Physics: Free Course
Focus: Physics foundations · Motion concepts
Beginner - Compare another approachFree MIT Course: Physics of Vibrations and Waves
Focus: 8.03SC Physics III: Vibrations and Waves Introduction · 8. Translation Symmetry
Intermediate - Explore a higher-level optionFree MIT Course: Plasma Physics Diagnostics
Focus: MIT Course: Plasma Physics Diagnostics
Professional
Compare course focus, level and study time
| Course | Level | Focus | Study time |
|---|---|---|---|
| This course — Electromagnetic Radiation: Free Physics Course | Intermediate | Electromagnetic waves · Light interactions · Wave comparison | 1h 40m of video; practice time is additional |
| High School Physics: Free Course | Beginner | Physics models · Motion analysis · Forces and momentum | 7h 39m of video; practice time is additional |
| Middle School Physics: Free Course | Beginner | Physics foundations · Motion concepts · Forces | 2h 10m of video; practice time is additional |
| Free MIT Course: Physics of Vibrations and Waves | Intermediate | 8.03SC Physics III: Vibrations and Waves Introduction · 8. Translation Symmetry · 17. Polarization, Polarizer | 30h 45m of video; practice time is additional |
| Free MIT Course: Plasma Physics Diagnostics | Professional | MIT Course: Plasma Physics Diagnostics | 29h 43m of video; practice time is additional |
Frequently asked questions
Is this course free to watch?
Yes. The public video lessons can be viewed in the WikiFree classroom. Free viewing does not include paid software, service subscriptions, provider membership benefits or a credential.
How long does the course take?
The 7 source videos total approximately 1h 40m. Allow additional time for pausing, practice, reviewing an example and checking your own result.
What background do I need?
Basic wave vocabulary, algebra and scientific graph reading are helpful. A notebook supports diagrams and comparisons. The classroom contains educational videos, with no supervised experiment, full physics assessment, school credit or professional qualification included.
Does watching the course award a certificate?
No. Video viewing and WikiFree progress tracking do not award a certificate, credit or an exam voucher.
Can I study on a phone?
Yes. The classroom has a responsive player and searchable lesson list. A larger screen and suitable practice environment are helpful for following software demonstrations or technical examples.
Provider: Khan Academy. Videos play from the Khan Academy channel on YouTube.
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