Ray diagrams

• What type of lenses cause light rays to diverge?

  Concave lenses
• What symbol is used to represent a concave lens in ray diagrams?

  A V shape with outward points
• What is the horizontal line through the middle of the lens called?

  The axis
• What are the focal points in relation to a lens?

  Points where light rays converge or diverge
• What is another name for the focal point?

  Principal focus
• What does the label '2f' represent in ray diagrams?

  Twice the distance of the focal point
• How do you start drawing a ray diagram for a concave lens?

  Draw incident rays from the object
• What happens to the ray that passes through the center of a concave lens?

  It continues straight without refraction
• How do you find the angle at which a ray is refracted in a concave lens?

  Draw a virtual ray to the focal point
• What do you do after drawing all light rays in a ray diagram?

  Find the point where they cross
• What can be said about the image formed by a concave lens?

  It is always virtual
• How is the image formed by a concave lens described?

  Upright and smaller than the object
• What type of lenses focus light onto a single point?

  Convex lenses
• How do the V shapes at the ends of a convex lens differ from a concave lens?

  They point inward, getting narrower
• What happens to the ray that passes through the middle of a convex lens?

  It continues straight without refraction
• What is the nature of the image formed by a convex lens when the object is more than two focal lengths away?

  Real, inverted, and smaller than the object
• What happens to the image if the object is placed exactly at two focal lengths from a convex lens?

  The image is real and the same size
• What occurs when the object is placed between the focal point and the lens in a convex lens setup?

  The image is virtual, upright, and larger
• What are the steps to draw a ray diagram for a concave lens?

  1. Draw the concave lens symbol.
  2. Add the axis and focal points.
  3. Draw incident rays from the object.
  4. Identify the refracted rays.
  5. Find the intersection point for the image.
  6. Comment on the image characteristics.
• What are the steps to draw a ray diagram for a convex lens?

  1. Draw the convex lens symbol.
  2. Add the axis and focal points.
  3. Draw incident rays from the object.
  4. Identify the refracted rays.
  5. Find the intersection point for the image.
  6. Comment on the image characteristics.
• What are the characteristics of images formed by concave and convex lenses?

  Concave lens:

  • Virtual
  • Upright
  • Smaller than the object

  
  

  Convex lens:

  • Real (if beyond 2f)
  • Inverted
  • Smaller than the object (if beyond 2f)
• What should you remember when drawing ray diagrams for exam objects?

  • Use simple objects like arrows
  • Draw rays from the top of the object
  • Ensure accuracy for full marks