If reflection takes place from optically denser medium, the change in phase is

A 5 cm thick glass slab is silvered at one of the surface to form a plane mirror. A point object is placed at a distance of $20cm $ from the unsilvered face. The image distance from the unsilvered face will be [R.I. of glass =1.5]

Light starting from a medium of refractive
index $  \mu  $ undergoes refraction into a medium of index $  \mu  $. If I and r stand for angle of incidence are refraction respectively :

A small object is enclosed in a sphere of solid glass  $8 cm$  in radius. It is situated  $2 cm$  from centre and is viewed from the side to which it is nearest. Where will it appear to be it  $\mu$  of glass  $= 1.5$ ?

When a light ray is refracted from one medium into another the wavelength change from $4500{ A }^{ 0 }$ to $3000{ A }^{ 0 }$ the critial angle for a ray from second medium to first medium is 

Which of the following statements is false?

A wave has velocity $u$ in medium $P$ and velocity $2u$ in medium $Q$. If the wave is incident in medium $P$ at an angle of $30^\circ$ then the angle of refraction will be

What is the angle of incidence if a ray of light is not deviated when it enters a block of glass?

An under water swimmer looks upward at an unobstructed overcast sky. The vertex angle does the sky appear to subtend at the eye of swimmer is (critical angle for water air interface is  $C$).

A mark is made on the surface of a glass sphere of diameter 10 cm and refractive index 1.5 . it its viewed through the glass from a potion directly opposite . the distance of the image of the mark from the centre of the sphere will be 

When a ray of light strikes the glass slab at $90^{\circ}$, it is seen that it does not deviate from its path. In such a situation :

The velocity of light in air is $3\times 10^{10} cm/\sec$. If the refractive index of glass with respect to air is $1.5$, then velocity of light in glass is

A bird in air looks at a fish vertically elow it and inside water. X is the height of the bird above the surface of water and Y the depth of the fish below the surface of water if refractive index of water with respect to air is $ \mu $. The distance of the fish as observed by the bird is 

A thin film of a liquid with refractive index $4/3$ produces interference pattern when light of wave length $450\ nm$ is incident normally. The minimum thickness of the film is approximately.

Point like object is observed using microscope angle subtended by objective with object is $20^{\circ}$. If oil of refractive index $1.4$ is kept between object and objective, numerical aperture will be ________.

A ray of light passes from a medium L to a medium K. No refraction of light occurs if the ray of light hits the boundary of these two media at the angle of incidence equal to ...............

The critical angle for refraction from medium -1 to air is ${ \theta  } _{ 1 }$ and that from medium -2 to air is ${ \theta  } _{ 2 }$. If medium -2 is denser then medium -1. Find the critical angle for refraction from medium -2 to medium. 

If any two media are optically exactly the same then; when light passes from one medium to another then:

Light, which is travelling along a normal, is ............ refracted

A vertical ray of light strikes the horizontal surface of water. What will be the angle of incidence?