In fig shows a thin beam of white light from a source S striking on one face of a prism.

(a) Complete the diagram to show the effect of prism on the beam and to show what is seen on the screen.

(b) If a slit is placed in between the prism and the screen to pass only the light of green colour, what will you then observe on the screen ?

(c) What conclusion do you draw from the observation in part (b) above ?

Open in App

Solution

(a) Constituent colours of white light are seen on the screen after dispersion through the prism.

(b) When a slit is introduced in between the prism and screen to pass only the light of green colour, only green light is observed on the screen.

(c) From the observation, we conclude that prism itself produces no colour.

Suggest Corrections

Similar questions

Q. Case: Pooja did an experiment with an equilateral glass prism in which she projected a narrow beam of white light source from one side of the surface of the prism and placed a screen on the other side of the prism. She observed certain patches of different colours on the screen. Later, she repeated the same experiment with a red-light source, however, she could only observe a red coloured patch on the screen. Again, she repeated the experiment with blue and green light sources, respectively, and could only see one colour patch on both the occasions.

Which of the following natural phenomena could she also relate to which is similar to the one she observed in the experiment?

Q. A student is performing an experiment with two triangular glass prisms. He places the first glass prism on its base. The second glass prism is placed upside down behind the first glass prism. When a beam of white light is allowed to fall on the first glass prism, then a patch of ordinary white light is obtained on a screen placed behind the second glass prism.
(a) Draw a ray diagram to show the above arrangement of two glass prisms and the light passing through them.
(b) What is the function of (i) first prism, and (ii) second prism, in this arrangement?

Q. In an experiment, Rakesh used an equilateral triangular glass prism and projected a narrow beam of white light source from one side of the surface of the prism. He placed a screen on the other side and saw many colours appearing as patches on the screen. But when he placed a second identical prism in an inverted position with respect to the first prism, he found a beam of white light emerging out from the other side of the second prism.

If Rakesh had passed a monochromatic light through the prism, then which of the following phenomenon would be observed?

(a) A beam of monochromatic light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base ?

(b) If white light is used in same way as in part (a) above, what change do you expect in the emergent beam ?

Q. White light is split into a spectrum by a prism and it is seen on a screen. If we put another identical inverted prism behind it in contact. What will be seen on the screen ?

Join BYJU'S Learning Program