A ray of light is moving from a rarer medium to a denser medium and strikes a plane mirror placed at 90^o to the direction of the ray as shown in the diagram.

i) Copy the diagram and mark arrows to show the path of the ray of light after it is reflected from the mirror.

ii) Name the principle you have used to mark the arrow to show the direction of the ray. 

The refractive index of glass with respect to air is 1.5. What is the value of the refractive index of air with respect to glass?

A ray of light is incident as a normal ray on the surface of separation of two different medium. What is the value of the angle of incidence in this case? 

i) Can the absolute refractive index of a medium be less than one?

ii) A coin is placed at the bottom of a beaker appears to be rasied by 4.0 cm. If the refractive index of water is 413, find the depth of water in the beaker?

i) No.

ii) Given,

Shift = 4 cm ;   ; Real depth = ?

We know that,

Shift = Real depth 

4 = Real depth  
Real depth = 

An object AB is placed between 2F₁ and F₁ on the principal axis of a convex lens as shown in the diagram.

Copy the diagram and using three rays starting from point A, obtain the image of the object formed by the lens.