La fisica🔥

• What is the term used for a lens that is thicker in the center than at the edges?


  Convex lens
• How does a convex lens affect light rays?


  A convex lens converges light rays towards a focal point
• What is the primary function of a convex lens in optical devices?


  To focus light and form images
• What is a concave lens?


  A lens that is thicker at the edges than at the center
• What happens to the intensity of radiation as temperature increases?


  The intensity of radiation increases
• Why are cloudy nights warmer than clear nights?

  Clouds reflect infrared radiation back to Earth
• What type of radiation do objects emit?

  Infrared radiation
• How do you draw a ray diagram for a lens?

  1. Draw a line from the top of the object through the center of the lens.
  2. Draw another ray from the top of the object parallel to the principal axis, which passes through the principal focus.
  3. If the rays do not meet, extend them with dotted lines to find the image location.
• What is the focal length of a lens?


  The distance from the center of the lens to the principal focus
• What does magnification have no units?


  Because it is a ratio
• What do focal lengths depend on?


  The strength of the lens
• What type of image does a convex lens produce when the object is between the lens and the principal focus?


  A virtual image
• What happens to light rays when they pass through a concave lens?


  Light rays diverge or spread out
• What is the image produced by a convex lens when the object is beyond the focal length?


  The image is magnified, inverted, and real
• What does a concave lens do to light rays?


  It causes light rays to diverge
• What is the shape of a convex lens?


  It is thicker at the center than at the edges.
• What is the primary function of lenses?


  Lenses refract light.
• What is the effect of a concave lens on the size of the image?


  The image is diminished
• What is the principle focus of a lens?


  The point where light rays converge or appear to diverge from
• How does the central ray behave when passing through a lens?


  The central ray passes through without being refracted.
• What happens to rays that pass along the normal through a lens?


  They pass through the principle axis at the center of the lens.
• How do you determine the location of the image in a ray diagram?


  By finding where the rays cross
• What is the principle focus of a lens?


  It is the point where rays converge after passing through the lens.
• What does it mean when an image is described as diminished?


  The image is smaller than the object.
• What is the effect of temperature on the emission of radiation?


  As temperature increases, the rate of emitting radiation increases
• What does it mean when an image is inverted?


  The image is upside down.
• What happens to rays that do not meet in a ray diagram?


  You draw dotted lines to extend the rays so they meet
• What is the nature of the image if the object is more than the focal length from the lens?


  The image is diminished, inverted, and real.
• What is the characteristic of a ray drawn from the top of an object through the center of a lens?


  It travels in a straight line without changing direction
• What is the significance of drawing a dotted line from the principal focus in a ray diagram?


  It shows the refraction of light
• What does radiation do to materials?


  It causes damage.
• What is the electromagnetic spectrum?


  It is the range of all types of electromagnetic radiation.
• What are the types of radiation in the electromagnetic spectrum?


  Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
• What is the speed of electromagnetic waves?


  The speed is $3 \times 10^8 \text{ m/s}$.
• Why does the direction of waves change in a black object?


  Because the light velocity decreases in that medium.
• What do ionizing waves do to atoms?


  They knock electrons off atoms.
• What is an oscilloscope used for?


  It is used to visualize electrical waves.
• Why are radio waves useful for radio and TV?


  They can travel long distances before being absorbed.
• How are radio waves produced?


  By electrons oscillating in electrical currents.
• Why are infrared waves used to cook food in microwaves?


  Infrared energy is easily absorbed by food.