A Ray Of Light Falls On A Transparent Glass Slab With Refractive Index (relative To Air) Of 1.62. The Angle Of Incidence For Which The Reflected And Refracted Rays Are Mutually Perpendicular Is: 

Monochromatic light of wavelength  travelling in a medium of refractive index n₁ enters a denser medium of refractive index n₂. The wavelength in the second medium is:    

When seen in green, the saffron and green portions of our national flag will appear to be: 

Light travels through a glass plate of thickness t and having refractive indexμ. If c be the velocity of light in vacuum, the time taken by the light to travel this thickness of glass is:

 are the electric permittivity and the magnetic permeability in a free space, ε and μ are the corresponding quantities in the medium, the index of refraction of the medium is:

A perfectly reflecting mirror has an area of 1 cm². Light energy is allowed to fall on it for one hour at the rate of 10 W/cm². The force that acts on the mirror is: 

A point source of light is placed 4 m below the surface of water of refractive index 5/3. The minimum diameter of a disc, which should be placed over the source, on the surface of water to cut off all light coming out of water is:

A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth when viewed through one face is 6 cm and when viewed through the opposite face is 4 cm. Then the refractive index of the material of the cube is:   

Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index is 1.5 is: 

A ray of light is incident on the surface of separation of a medium with the velocity of light at an angle 45^o and is refracted in the medium at an angle 30^o. What will be the velocity of light in the medium

A concave mirror of focal length f produces an image n times the size of the object. If the image is real, then the distance of the object from the mirror is: