12.5 Electromagnetic Waves

• The oscillation direction of the electric field in an electromagnetic wave is perpendicular to the direction of propagation
• Arrange the following waves in the electromagnetic spectrum from longest to shortest wavelength:

  1️⃣ Radio Waves

  2️⃣ Microwaves

  3️⃣ Infrared

  4️⃣ Visible Light

  5️⃣ Ultraviolet

  6️⃣ X-rays

  7️⃣ Gamma Rays
• Microwaves are used in satellite communication and microwave ovens
• Ultraviolet waves are used for disinfection, fluorescence, and curing
• Changing magnetic fields induce electric fields
• What does the electromagnetic spectrum encompass?

  Frequencies and wavelengths
• Visible light has intermediate energy and wavelengths.


  True
• What creates an electric field?

  Electric charges
• What is the unit of amplitude for electromagnetic waves?

  Volts/meter or Tesla
• What is a key feature of radio waves that allows them to penetrate walls?

  Low energy, long wavelengths
• Gamma rays can damage living cells due to their extremely high energy.


  True
• What do electromagnetic waves interact with when they encounter matter?

  Charged particles and magnetic materials
• What is the wavelength range of visible light?

  400 - 700 nm
• Which type of electromagnetic waves has the highest frequency?

  Gamma Rays
• What affects magnetic fields created by moving charges?

  Moving charges and magnetic materials
• What are common uses of microwaves?

  Radar, satellite communication
• Gamma rays have extremely short wavelengths and are used in cancer treatment
• Match the field type with its creator:

  Electric field ↔️ Electric charges

  Magnetic field ↔️ Moving electric charges
• The speed of electromagnetic waves in a vacuum is approximately 3.00 × 10^8 m/s.


  True
• What type of electromagnetic wave is sensitive to heat?

  Infrared
• What are electromagnetic waves composed of?

  Oscillating electric and magnetic fields
• Electromagnetic waves transport energy through the oscillation of electric and magnetic fields.

  True
• What frequency range do radio waves fall under in the electromagnetic spectrum?

  3 kHz - 300 GHz
• Infrared waves are used in night vision and thermal imaging.

  True
• Match the wave type with its key property or application:

  Radio Waves ↔️ Broadcasting and communication

  Microwaves ↔️ Radar and satellite communication

  Visible Light ↔️ Illumination

  X-rays ↔️ Medical imaging
• Moving electric charges produce magnetic fields.


  True
• Radio waves have a frequency range of 3 kHz to 300 GHz
• Which type of electromagnetic wave is used in fluorescence?

  Ultraviolet
• A changing magnetic field induces an electric field.


  True
• The wavelength of an electromagnetic wave is given by the formula λ = c/f
• Microwaves are used in microwave ovens to heat water