waves

• What is amplitude in waves?

  Maximum displacement from equilibrium position
• What is the angle of incidence?

  Angle between incident ray and normal
• What is the angle of reflection?

  Angle between reflected ray and normal
• When does an object appear black?

  If it absorbs all wavelengths of radiation
• What are colour filters?

  Filters that absorb certain wavelengths and transmit others
• How is colour determined?

  By frequency and wavelength
• What does constant temperature mean?

  Absorbing radiation at the same rate as emitting
• What is a convex lens?

  Lens that brings parallel rays to focus
• What is diffuse reflection?

  Reflection from a rough surface causing scattering
• What is echo sounding?

  Technique using sound waves to detect objects underwater
• What are electromagnetic waves?

  Transverse waves transferring energy from source to absorber
• What is the focal length?

  Distance from lens center to principal focus
• What is frequency in waves?

  Number of waves passing a point in a second
• What is the unit of frequency?

  Hertz
• What is human hearing range?

  20Hz to 20kHz
• What is infrared radiation?

  Radiation emitted and absorbed by all objects
• What is ionising radiation?

  Radiation causing gene mutation and cancer
• What is a lens?

  Object forming an image through light refraction
• What are longitudinal waves?

  Waves with oscillations parallel to direction of travel
• How is magnification calculated?

  Image height over object height
• What are microwaves used for?

  Satellite communications and cooking food
• What is the normal in optics?

  Imaginary line perpendicular to a boundary
• What are P-waves?

  Longitudinal seismic waves traveling through solids and liquids
• What is a perfect black body?

  Object absorbing all incident radiation
• What is the period of a wave?

  Time for one complete wave to pass a point
• What is radiation dose?

  Measure of risk from radiation exposure
• What are radio waves used for?

  Television and radio signals
• What is reflection in waves?

  When a wave bounces off a boundary
• What are S-waves?

  Transverse seismic waves that cannot travel through liquids
• What are seismic waves?

  Waves produced by earthquakes
• What is specular reflection?

  Reflection from a smooth surface in one direction
• What are transverse waves?

  Waves with oscillations perpendicular to direction of travel
• What is ultrasound scanning?

  Technique using ultrasound waves for imaging
• What are ultrasound waves?

  Waves with frequency higher than 20kHz