Define dispersion of light. How would you identify monochromatic light and composite light with the help of a prism? [1 + 2]

Write down the relationship between relative refractive index and absolute refractive index. On which factors does the relative refractive index of a medium depend? [1 + 2] OR Show that if a monochromatic light ray passes symmetrically through an equilateral prism then the angle of deviation of that ray will be minimum

What is long-sightedness? What type of lens is used to remedy this defect? [2+1]

What type of lens is used as a magnifying glass?

Why is the red colour selected for danger signal lights?

For which value of the angle of incidence in refraction of light is Snell's law not applicable?

Which type of mirror produces a virtual, diminished and erect image? (a) Plane mirror (b) Concave mirror (c) Convex mirror (d) Parabolic mirror

Explain with a suitable ray diagram the process of formation of image by a concave lens.

Explain with a diagram why the sky appears blue.

For the same angle of incidence, the angles of refraction in three different media A, B and C are 30°, 45° and 60° respectively. In which medium is the speed of light minimum and why? [3]

Write two causes of short-sightedness or myopia. Which type of lens is used to correct it? [2+1]

Where is the image formed if the object is placed in between f and 2f of a convex lens ?