PhysicsGrade 10Light and Waves

Lens Bench: Ray Diagram and Image Formation

Move an object in front of a converging lens, change focal length, and inspect image distance, magnification, orientation, and ray paths.

SimulationsLab index
Textbook unitWaves, light, and image formationMapped to optics and wave sections when available
Keywordslight, lens, ray, image, focal lengthMapped to available textbook headings
Practice modeManipulate, measure, explainUse the controls, then read the live evidence

Physics · Grade 9

Move the object and trace the image rays

Adjust object distance, focal length, and height to see how a converging lens forms real and virtual images.

ImageReal inverted
1

Converging lens: set f = 20 cm, object at 60 cm. Is the image real or virtual? What does 1/f = 1/do + 1/di predict?

2

Focal point: move the object to exactly 20 cm (= f). Where does the image form? Why does the formula break down here?

3

Virtual image: place the object inside the focal length (< 20 cm). Is the image magnified or reduced? Record magnification.

PhETGeometric Optics
Full screen ↗
FFObject⟺ImageDrag object or F to explore
Optics insight

Thin lens: 1/f = 1/do + 1/di → di = 22.9 cm. M = −di/do = -0.64×.

Image typeReal inverted
Image distance22.9 cm
Magnification-0.64x
Image height5.1 cm
Lens equation1/f = 1/do + 1/di

Lab task

Find one setup that makes a real inverted image and one setup that makes a virtual upright image. Record both and compare magnification.

Observation rule

When the object is outside the focal length, a converging lens can form a real inverted image. Inside the focal length, the image becomes virtual and upright.

Mission

What to prove in this lab

  1. Relate object distance, focal length, and image distance using a ray diagram.
  2. Predict when an image is real, virtual, inverted, or upright.
  3. Use magnification to compare object height and image height.