Advertisements
Advertisements
प्रश्न
State the cause of dispersion of white light passing through a glass prism. How did Newton show that white light of sun contains seven colours using two identical glass prisms. Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the focus of the first prism.
उत्तर
Different colours of light bend through different angles with respect to the incident ray as they pass through a prism. The red light bends the least, while the violet bends the most. Thus, the rays of each colour emerge along different paths and thus become distinct. This is the cause of dispersion of white light passing through a glass prism.
Isaac Newton used two glass prims, with one prism in inverted position to show that white light of the Sun contains seven colours. The set-up has been shown below:-
When white light of the Sun passes through the first prism, it gets dispersed into seven colours. When all the seven colours of the spectrum were passed through the second prism, Newton found a beam of white light emerging from the other side of the second prism. This observation gave Newton the idea that the sunlight is made up of seven colours.
संबंधित प्रश्न
Describe an activity to show that colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also draw ray diagram to show the recombination of the spectrum of white light.
In the figure given alongside, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum YX on the screen.
State the colour seen (i) at X, and (ii) at Y.
A ray of light moving from an optically rarer to a denser medium
The seven colours in the spectrum of sunlight in order, are represented as :
- 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?
- If white light is used in the same way as in part (a) above, what change do you expect in the emergent beam?
- What conclusion do you draw about the nature of white light in part (b)?
What conclusion do you draw about the nature of white light in part (b)?
The phenomenon of splitting of light into its component colours is ___________ .
In the diagram, a narrow beam of white light is incident on a right-angled isosceles prism. The critical angle of the material of prism for the yellow colour of white light is 45°. Complete the diagram to show the path of blue, yellow, and red colours of white light till they emerge out of the prism.
Define dispersion of light.
Which one of the following is involved for the formation of rainbow in the sky?
