Electromagnetic Waves Cheat Sheet

Key Definitions

• Electromagnetic Waves: Waves that propagate through space, consisting of oscillating electric and magnetic fields.

• Frequency (f): Number of waves passing a point per second, measured in Hertz (Hz).

• Wavelength (λ): Distance between successive crests of a wave, measured in meters (m).

• Amplitude: Maximum displacement of a wave from its rest position.

Important Concepts

Properties of Electromagnetic Waves

• Travel at the speed of light c = 3 x 10^8 m/s in a vacuum.

• Can propagate through a vacuum and do not require a medium.

• Exhibit transverse wave characteristics (electric field ⊥ magnetic field).

Electromagnetic Spectrum

• Ranges from radio waves to gamma rays.

• Order: Radio < Microwave < Infrared < Visible < Ultraviolet < X-rays < Gamma rays

• Each type has different applications (e.g., radio for communication, X-rays for imaging).

Key Formulas

• c: speed of light (3 x 10^8 m/s)

• f: frequency (Hz)

• λ: wavelength (m)

E = h × f

• E: energy of photon (Joules)

• h: Planck's constant (6.63 x 10^-34 J·s)

Common Mistakes to Avoid

Common Mistake: Confusing wavelength and frequency; remember they are inversely related.

Memory Tricks

Tip: "RIVUXG" — Order of the electromagnetic spectrum:

• Radio

• Infrared

• Visible

• Ultraviolet

• X-rays

• Gamma rays

Key Diagrams

  E-field
    |
    |      -----> Direction of wave propagation
    |     /
    |    /
    |   /  B-field
    |  /
    | /
    |/____________________

• E-field: Electric field oscillation

• B-field: Magnetic field oscillation

Remember: E and B fields are always perpendicular to each other and to the direction of wave propagation.