Electromagnetic

• What is the electromagnetic spectrum?

  It is the range of electromagnetic waves.
• What are the main components of the electromagnetic spectrum?

  • Radio waves
  • Microwaves
  • Infrared
  • Visible light
  • Ultraviolet
  • X-rays
  • Gamma rays
• Who discovered the visible spectrum?

  Isaac Newton
• When was infrared heat waves discovered?

  In 1800
• How did Herschel discover infrared waves?

  By measuring temperature in the visible spectrum.
• What did Johann Ritter discover?

  Ultraviolet rays
• What is the significance of silver chloride in Ritter's experiment?

  It breaks down to black silver when exposed to light.
• Who discovered radio waves and when?

  Heinrich Hertz in 1888
• How do electromagnetic waves travel?

  At the speed of light in a vacuum.
• What is the mnemonic to remember the order of electromagnetic waves?

  "Reading Magazines Is Lousy Unless Extremely Good"
• What does ROY G BIV represent?

  The colors of the visible spectrum.
• What are the uses of different electromagnetic waves?

  • Radio waves: Broadcasting and communications
  • Microwaves: Cooking and satellite communications
  • Infrared: Thermal imaging and remote controls
  • Visible light: Vision and photography
  • Ultraviolet: Disinfecting and detecting forgeries
  • X-rays: Medical imaging
  • Gamma rays: Cancer treatment
• How do microwaves help monitor rainfall?

  By measuring absorption by water molecules.
• What do infrared sensors detect?

  Temperature differences of surfaces.
• How are X-rays used in medical imaging?

  They expose photographic plates to show fractures.
• What happens to paper exposed to ultraviolet light?

  It fluoresces, helping detect forgeries.
• What is the relationship between wave frequency and damage?

  Higher frequency waves cause more damage.
• What can excessive exposure to microwaves cause?

  Internal heating of tissue.
• What are the three types of UV radiation?

  UVA, UVB, UVC
• What is the most damaging type of UV radiation?

  UVC
• What can prolonged exposure to UV radiation cause?

  Skin cancer and cataracts.
• How do X-rays and gamma rays affect cells?

  They can kill normal cells and cause cancer.
• What is the speed of electromagnetic waves in a vacuum?

  $3 \times 10^8 \text{ m/s}$
• How can you calculate the wavelength of electromagnetic waves?

  Using the wave speed equation.
• What is the equation for wave speed?

  $v =$$f \times \lambda$
• What is the significance of the electromagnetic spectrum being continuous?

  It means frequencies and wavelengths are not precisely defined.
• What is white light composed of?

  All colors of the visible spectrum.
• How does infrared radiation relate to temperature?

  Hotter objects emit more infrared radiation.
• What is the role of infrared in remote controls?

  It transmits signals to devices.
• How do microwaves function in cooking?

  They heat food by exciting water molecules.
• What is the primary use of radio waves?

  To transmit radio and TV programmes.
• What happens to the temperature of water in different cans exposed to sunlight?

  The can with a matte surface absorbs more infrared radiation.
• What is the effect of infrared radiation on the skin?

  It can cause burns with excessive exposure.
• How do different surfaces affect infrared radiation absorption?

  Matt surfaces absorb more than shiny surfaces.
• What is the purpose of the experiment with cans and water?

  To determine the best emitter and absorber of infrared radiation.
• What is the significance of the wave speed equation?

  It allows calculation of frequency or wavelength.
• How does the electromagnetic spectrum relate to energy transfer?

  Electromagnetic waves transfer energy from a source to an absorber.
• What is the effect of high-frequency waves on living cells?

  They can cause damage with excessive exposure.
• What is the role of the ozone layer regarding UV radiation?

  It absorbs most UVC radiation.
• What is the relationship between amplitude and energy in waves?

  Higher amplitude means more energy carried.