Lenses and Their Rays
Part of the Optics, Waves and Modern Physics section of Coddy's Physics journey. Lesson 12 of 53.
A converging lens sends light parallel to its axis through the focus F, a distance f away.
Three rays: parallel to the axis, then through F; through the centre, straight on; through the near F, then parallel.
They meet at the tip of the image: real and upside down. The centre ray gives the size:
hᵢ / hₒ = |v| / u
Challenge
An object 2 cm tall stands 30 cm in front of a converging lens, and its image forms 60 cm behind it. How tall h_i is the image?
Try it yourself
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Optics, Waves and Modern Physics
1Reflection and Refraction
Reflection of LightThe Refractive IndexSnell's LawTotal Internal ReflectionDispersionApparent DepthRecap - Optical Fiber4Mechanical Waves
What a Wave IsTwo Graphs of a WaveWhen Pulses MeetInterferenceStanding WavesHarmonicsRecap - Guitar String