Optics (Physics) Part-I

Land covered with fresh snow reflects back more sunlight as compared to other three. Fresh snow and ice reflect about 80-85% of the sunlight. The skin of skiers is irradiated by sunlight from all sides, since the snow does not take up the light but reflects it and remains cold.

"Albedo' (Latin meaning-whiteness) is the name given by the scientists to this ability of surfaces to reflect light. The albedo is particularly high for snow and ice.

Holography is a technique of producing a three-dimensional image of an object. Holography can work with sound, light or any wavelength.

Holography is popularly used for preserving the transcripts and for Microfiche (a flat piece of film containing microphotographs of the pages of newspaper, catalogue or other). It is also been used for making three-dimensional feature films.

Holography is a technique of producing a three-dimensional image of an object. Holography can work with sound, light or any wavelength.

Holography is popularly used for preserving the transcripts and for Microfiche (a flat piece of film containing microphotographs of the pages of newspaper, catalogue or other). It is also been used for making three-dimensional feature films.

Roster scan is used in CRT (Cathode Ray Tube) monitors, in which electronic beam is projected by electronic gun to generate an image on the screen.

Raman effect deals with the light rays passing through all transparent medium. According to this, a beam of light traverses a dust-free transparent sample of a chemical compound, a small fraction of light emerges in directions other than that of the incident (incoming) beam.

The lens used in CD player emit ultraviolet laser beams which produce sound after reflecting through the bright surface of CD.

When a CD is viewed in sunlight, rainbow-like colours in seen. To understand this phenomenon one has to understand the construction of CD. A CD is a thin, circular disc of metal and plastic. It is actually made of three layers. Most of a CD is made from a tough, brittle plastic called polycarbonate.

Sandwiched in the middle there is a thin layer of aluminium. Finally, on the top of aluminium, is a protective layer of plastic and lacquer. It acts like a thin film, which is responsible for reflection and diffraction of light.

As we know that the scattering or deviation δ = (n - 1) A. Hence, the light of shorter wavelength is scattered much more than the light of longer wavelength. The speed of visible light in water = 2.25 × 10⁸ m/sec and the speed of light in vacuum = 3.0 × 10⁸ m/sec.

Thus, it is clear that the speed of visible light in water is 0.75 times the speed of light in vacuum. So, the statement 1 and 2 are wrong while statement 3 and 4 are correct. Thus, the correct answer is option (d).

Statement (A) is correct but reason (R) is false because the image formed on the retina of eye persists for about 1/16 of a second after the removal of the stimulus.

Television signals cannot be received beyond a certain distance because the surface of the Earth is curved, due to this the signals moves further without hitting the Earth's surface.