Waves

• What are the two types of waves discussed?

  Transverse and Longitudinal Waves
• How do waves transfer energy?

  In the direction they are travelling
• What type of vibrations do transverse waves have?

  Sideways vibrations
• What type of vibrations do longitudinal waves have?

  Parallel vibrations
• What is the formula for wave speed?

  Wave Speed = Frequency × Wavelength
• How can you measure the speed of sound using an oscilloscope?

  By measuring the wavelength and frequency
• What are the steps to measure the speed of sound using an oscilloscope?

  1. Set up the oscilloscope with microphones.
  2. Move one microphone away until waves align.
  3. Measure the distance for one wavelength (λ).
  4. Use the formula \( v = fλ \) to find speed.
  5. Compare results with the speed of sound in air (330 m/s).
• What happens when waves arrive at a boundary between two materials?

  They can be absorbed, transmitted, or reflected
• What is absorption in terms of wave behavior?

  The wave's energy warms the material
• What does it mean for waves to be transmitted?

  The wave continues traveling through the new material
• What is reflection in wave behavior?

  The wave bounces back after hitting a boundary
• What is the rule for reflected waves?

  Angle of incidence = Angle of reflection
• What is the angle of incidence?

  The angle between the incoming wave and the normal
• What is the normal in wave reflection?

  An imaginary line perpendicular to the wave's surface
• What is specular reflection?

  Reflection by a smooth surface
• What is diffuse reflection?

  Reflection by a rough surface
• What happens to light reflected by a rough surface?

  It appears matte and dull
• What is the speed of light in a vacuum?

  It travels at the speed of light
• What is refraction?

  Waves changing direction at a boundary
• What affects how much a wave is refracted?

  Differences in material density
• What are radio waves used for?

  Communication and entertainment
• How are radio waves produced?

  By oscillating electric and magnetic fields
• What is a transmitter in radio wave production?

  The object creating the radio waves
• What happens when radio waves reach a receiver?

  Electrons in the aerial oscillate
• What is the frequency of the alternating current related to?

  It is equal to the frequency of the radio wave
• What is the wavelength of radio waves?

  Longer than about 10 cm
• How do long waves behave in terms of diffraction?

  They can bend around the Earth's surface
• What is the role of Bluetooth in radio waves?

  It sends calls over short distances
• What is the use of microwaves in communication?

  They penetrate the Earth's atmosphere
• How do microwave ovens heat food?

  By absorbing microwaves in water molecules
• How do infrared thermometers work?

  They detect infrared radiation to measure temperature
• How do electric heaters emit heat?

  By emitting infrared radiation when current flows
• What does infrared radiation do?

  It increases or monitors temperature
• What is the principal focus of a convex lens?

  The point where rays converge
• What is the focal length of a lens?

  The distance from the lens to the principal focus
• What are the two main types of lenses?

  Convex and Concave lenses
• What are the three rules for refraction in a convex lens?

  1. Incident ray parallel to axis refracts through focus.
  2. Incident ray through center continues in same direction.
  3. Incident ray through focus refracts parallel to axis.
• What are the three rules for refraction in a concave lens?

  1. Incident ray parallel to axis travels in line with focus.
  2. Incident ray towards focus refracts parallel to axis.
  3. Incident ray through center continues in same direction.
• What is a virtual image?

  An image formed by diverging rays
• What is the visible spectrum?

  The part of EM waves our eyes detect