Convex & Concave Ray Diagrams Flashcards
All 6 cards in this deck
Give three words that describe the image formed by a concave lens.
Virtual, upright and diminished.
In a ray diagram, what shows that an image is virtual?
The refracted rays have to be traced backwards (dashed construction lines) to where they appear to meet.
How does the size of the image change as an object moves further away from a concave lens?
It decreases.
True or false? A graph of image distance against object distance for a convex lens shows the two quantities are inversely proportional.
False. The image distance decreases as object distance increases, but the relationship is not inverse proportionality.
What are the steps to locate the image in a convex lens ray diagram?
e.g. an object standing beyond the focal length
- Ray from the top of the object parallel to the axis → refracts through the principal focus.
- Ray from the top of the object through the centre of the lens → straight on.
- Image is where the two rays cross: real and inverted.
Where must an object be placed for a convex lens to form a real image?
Further from the lens than the focal length (beyond the principal focus).