Fiches de ce paquet (33)

• What is the definition of concave lenses?

  Concave lenses curve inwards and make parallel rays of light diverge.
  optics lenses
• What is the definition of convex lenses?

  Convex lenses curve outwards and make parallel rays of light converge at a point.
  optics lenses
• What is specular reflection?

  Reflection from a smooth surface in a single direction.
  optics reflection
• What is diffuse reflection?

  Reflection from a rough surface causing scattering of light.
  optics reflection
• What do transparent objects do?

  Transparent objects transmit visible light.
  optics properties
• What do translucent objects do?

  Translucent objects transmit visible light but scatter or refract light rays inside them.
  optics properties
• What do opaque objects do?

  Opaque objects do not transmit visible light but absorb and reflect it.
  optics properties
• What does the color of an object depend on?

  The wavelengths they transmit and reflect.
  optics color
• How do coloured filters work?

  By absorbing certain wavelengths of light and transmitting others.
  optics filters
• What is the focal length of a lens?

  The distance from the center of the lens to the principal focus.
  optics lenses
• What type of images do concave lenses form?

  Concave lenses always form virtual images.
  optics images
• What types of images do convex lenses form?

  Convex lenses can form either real or virtual images.
  optics images
• What is the formula for magnification?

  Magnification = image height / object height.
  optics magnification
• What are the characteristics of images formed by lenses?

  Images can be magnified or diminished, upright or upside down (inverted).
  optics images
• What conditions are needed for accurate investigations of light?

  Use low light conditions, a distant slit from the bulb, a sharp pencil, and measure angles from the normal line.
  optics experiments
• What happens to wave fronts when a wave slows down at a boundary?

  The wave fronts become closer together.
  optics wavefronts
• What occurs when a wave crosses a boundary at an angle?

  One end of the wave front changes speed before the other, changing the wave's direction.
  optics wavefronts
• What happens to a refracted ray if it slows down at a boundary?

  The refracted ray bends towards the normal.
  optics refraction
• What happens to a refracted ray if it speeds up at a boundary?

  The refracted ray bends away from the normal.
  optics refraction
• What occurs when a wave travels at a right angle to the boundary?

  It changes speed but not direction.
  optics refraction
• What is the difference between a concave and convex lens?

  • Convex: bulges out in the middle
  • Concave: thinner in the middle than at the edges
  optics lenses
• What does a convex lens do to parallel rays of light?

  Light converges (comes together) at the principal focus.
  optics lenses
• What does a concave lens do to parallel rays of light?

  Light diverges (spreads out) so they appear to have come from the principal focus.
  optics lenses
• What is the focal length of a lens?

  Distance from the centre of the lens to the principal focus.
  optics lenses
• What kind of images do concave and convex lenses produce?

  • Concave: virtual
  • Convex: real or virtual
  optics lenses
• What properties do all EM waves of the same colour share?

  Same range of wavelengths and frequencies.
  physics waves
• What four things can happen to visible light when it hits an object?

  • Transmitted
  • Absorbed
  • Reflected
  • Refracted
  optics light
• What is the difference between specular and diffuse reflection?

  • Specular: reflection from smooth surface
  • Diffuse: reflection from rough surface
  optics reflection
• What words describe an object that transmits visible light?

  Transparent or translucent.
  optics light
• Why does an object appear opaque?

  Does not transmit visible light – absorbs and reflects it.
  optics light
• How do colour filters work?

  Absorb certain wavelengths of light, transmit others.
  optics filters
• What is refraction?

  Waves change speed and direction as they cross the boundary from one substance to another due to the change in velocity.
  optics refraction
• What happens to the direction of a refracted EM wave when it slows down?

  Bends towards the normal.
  optics waves