Fill in the blanks by choosing the most appropriate word/phrase.

1. Convex lens is also called a _______________ lens.
2. The point within a lens through which a ray of light passes and emerges without any deviation is known as _______________.
3. Rainbows are formed due to ______________ of light.
4. When a ray of light passes from a rarer to a denser medium, the speed of light ___________________.
5. When a ray of light passes from a denser to a rater medium, the angle of incidence is ______________ the angle of refraction.
6. When clear water is poured in an empty vessel, its bottom appears to be ________________.
7. The distance between the optical centre and the principal focus is known as _______________.
8. ______________ help(s) to adjust the focul length of the eye lens.
9. When bright light falls into a person's eye, the size of the pupil ________________.
10. To correct hypermetropia, _________________ lenses are used.
11. The final image in an astronomical telescope is _________________ the original object.
12. If a beam of white light is pased through a _________________, it splits into its component colours.

Find the odd one out and give your reasons.

1. Telescope, microscope, magnifying glass, glass slab
2. Hypermetropia, presbyopia, retina, myopia
3. Retina, optic nerve, optic centre, iris
4. Principal focus, optic centre, refractive index, centre of curvature

Correlate the following.

1. Short-sightedness : Behind the retina :: Long-sightedness : _______________________.
2. Iris : Pupil :: Ciliary muscle : _________________
3. Concave lens : Myopia :: _________________ : Hypermetropia
4. Convex lens : Erect magnified image :: Concave lens: ________________
5. Convex lens : Convergene of rays :: Prism : ___________________

What happens when a light ray travels through glass?

State the laws of refraction.