Advertisements
Advertisements
प्रश्न
A prism causes dispersion of white light while a rectangular glass block does not. Explain.
Advertisements
उत्तर
In a prism, the refraction of light takes place at the two slant surfaces. The dispersion of white light occurs at the first surface of the prism where its constituent colours have deviated through different angles. At the second surface, these split colours suffer the only refraction and they get further separated. But in a rectangular glass block, the refraction of light takes place at the two parallel surfaces. At the first surface, although the white light splits into its constituent colours on refraction, these split colours on suffering refraction at the second surface emerge out in form of a parallel beam, which gives an impression of white light.
संबंधित प्रश्न
Why is the colour red used as a sign of danger?
Name three factors on which the deviation produced by a prism depends and state how does it depend on the factors stated by you.
Which colour of white light travels fastest in glass?
In following figure shows a thin beam of white light from a source S striking on one face of a prism.

Complete the diagram to show effect of prism on the beam and to show what is seen on the screen.
In following diagram shows a thin beam of white light from a source S striking on one face of a prism.

What conclusion do you draw from the observation in part (b) above?
If a monochromatic beam of light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base?
Write the approximate wavelengths for blue.
What is understood by the term dispersion of light? What is its cause?
Which colour of white light travels slowest, in glass?
The wavelengths for the light of red and blue colours are nearly 7·8 × 10-7 m and 4·8 × 10-7 m respectively.
Which colour has greater speed in glass?
