Reading Time: < 1 minuteSpeed of Light (
Energy of a Photon (
Electromagnetic Waves: Exploring Light, Infrared, and Microwaves in A-Level Science
What Are Electromagnetic Waves?
Electromagnetic waves are oscillations of electric and magnetic fields that travel through space without requiring a medium.
Properties of Electromagnetic Waves
Speed of Light (
)
)Electromagnetic waves travel at 
in a vacuum:
![\[ c = f\lambda \]](https://skinattuition.co.uk/core/ql-cache/quicklatex.com-1fa59ae47eef62ff97b82f9853a6ff8e_l3.png "Rendered by QuickLaTeX.com")
Where:
: Frequency (
).
: Wavelength (
).
: Frequency (
).
: Wavelength (
).Energy of a Photon (
)
) ![\[ E = hf \]](https://skinattuition.co.uk/core/ql-cache/quicklatex.com-1ddb7c6970780882b0f184db4090b065_l3.png "Rendered by QuickLaTeX.com")
Where 
: Planck’s constant.
Applications of Electromagnetic Waves
Light Waves
- Used in optics, lasers, and photography.
Infrared Radiation
- Employed in thermal imaging and remote controls.
Microwaves
- Essential for communication (Wi-Fi) and cooking.
Example Problem
Calculate the energy of a photon with a wavelength of 
.
- Formula:
![\[ E = hf = h\frac{c}{\lambda} \]](https://skinattuition.co.uk/core/ql-cache/quicklatex.com-c08cc0ba48a873a9863c88df2520389e_l3.png "Rendered by QuickLaTeX.com")
- Substitute Values:
![\[ E = \frac{6.63 \times 10^{-34} \cdot 3.0 \times 10^8}{600 \times 10^{-9}} = 3.32 \times 10^{-19} \, \text{J} \]](https://skinattuition.co.uk/core/ql-cache/quicklatex.com-a02fa4cd296d32c9241962a989447d32_l3.png "Rendered by QuickLaTeX.com")
Common Mistakes in Electromagnetic Wave Problems
- Forgetting to convert wavelength to meters.
- Mixing up the energy formula for photons with classical energy equations.
- Ignoring the relationship between wavelength and frequency.
Practice Questions
- Calculate the frequency of a microwave with a wavelength of
. - Explain how infrared radiation is used in thermal imaging.
- Describe one application of electromagnetic waves in communication.
.
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