Fill in each blank with the correct word from the lesson.

1. A _______ is thinner at the centre — it diverges light rays so they appear to come from a virtual focal point in front of the lens.
2. _______ is the bending of light when it passes from one medium to another — for example from air into glass or water.
3. Concave _______ always form smaller, upright virtual images.
4. A lens is a curved piece of _______ material that refracts light in controlled ways.
5. Refraction and Lenses is an important topic in _______.

Choose the best option for each question.

1. Why does light bend when it enters water from air?
   a) It changes colourb) It changes speedc) The water pushes itd) The normal line redirects it
2. Which lens is used to correct short-sightedness?
   a) Convex lensb) Plane lensc) Concave lensd) Bifocal lens
3. What is the role of the retina in the eye?
   a) Controls the amount of light enteringb) Bends light to focus itc) Converts light into nerve signalsd) Holds the lens in place

Write T for True or F for False in the brackets.

1. It changes speed is one of the key concepts in the lesson on Refraction and Lenses.
2. It changes colour is the main topic of this lesson.
3. A concave lens is thinner at the centre — it diverges light rays so they appear to come from a virtual focal point in front of the lens.
4. A Convex lens is thinner at the centre — it diverges light rays so they appear to come from a virtual focal point in front of the lens.

1. In your own words, explain what Refraction and Lenses means.
2. List two things you learned from this lesson on Refraction and Lenses.