Electromagnetic waves are oscillations of electric and magnetic fields that travel through space at the speed of light. They include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Key Formulas:

• c = λf - Wave speed
• E = hf - Photon energy
• E = hc/λ - Energy from wavelength

Units:

• Wavelength: m, nm, μm
• Frequency: Hz, kHz, MHz, GHz
• Speed: m/s, km/s
• Energy: J, eV

Applications:

• Radio, TV, and wireless communication
• Optics and lasers
• Medical imaging (X-rays, MRI)
• Remote sensing and astronomy
• Solar energy and photovoltaics