# Electromagnetic waves for OCR A-level Physics

1. Basics of electromagnetic waves
2. The Electromagnetic Spectrum

Electromagnetic waves are transverse waves, so particles move perpendicular to the direction of energy transfer. Their oscillations are changes in electrical and magnetic fields which are in phase with each other and vibrate at 90° from each other.

Electromagnetic waves run along a spectrum of different wavelengths. All of these waves travel at the same speed in a vacuum, but the different frequencies and wavelengths means that each of the various waves on the spectrum have different properties.

# 1

The human eye is only able to see a small range of wavelengths within the electromagnetic spectrum. How does the eye experience these different wavelengths in the visible light part of the spectrum?

The eye experiences different wavelengths as different colours. Red light has the longest wavelength and blue light has the shortest.

# 2

What is the range of frequencies in the waves of the EM spectrum?

from 10⁴ Hz to 10²⁰ Hz

# 3

A wave has a wavelength of 1 m, what type of wave is it?

# 4

Fill in the gaps in the given diagram with the following types of wave: Microwave, Gamma rays and Ultraviolet.

A. Gamma rays. B. Ultraviolet. C. Microwaves

# 5

Fill in diagram in the correct order with the waves: ultraviolet, infrared and visible light.

Infrared has the shortest wavelength, followed by visible light, and UV has the longest wavelength.

A = ultraviolet, B = visible light, C = infrared

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