Advertisements
Advertisements
Question
What is the cause of the dispersion of white light through a glass prism? Draw a ray diagram to show the path of light when two identical glass prisms are arranged together in an inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the faces of the prisms.
Advertisements
Solution
The dispersion of white light occurs because of the varying speeds of different colored lights through different media. White light consists of seven colors. The speeds of these colored lights are the same through the air. However, their speeds vary in other media. Therefore, when white light enters from air to a glass prism then its component colors get refracted by different angles. As a result, dispersion occurs.
A ray diagram to show the path of light when two identical glass prisms are arranged together in an inverted position with respect to each other and a narrow beam of white light is allowed to fall obliquely on one of the faces of the prisms is given below:
When white light of the Sun passes through the first prism, it gets dispersed into its seven component colors. When all the seven colors of the spectrum pass through the second prism then a beam of white light emerges from the other side of the second prism.
APPEARS IN
RELATED QUESTIONS
What will happen if another similar glass prism is placed upside down behind the first prism?
What is spectrum? What is the name of glass shape used to produce a spectrum?
Which of the following colour of white light is least deviated by the prism?
(a) green
(b) violet
(c) indigo
(d) yellow
In figure AO is the ray of white light falling on a prism PQR. Complete the diagram till the light emerges out from the prism and falls on the screen.
Write three conditions necessary to obtain a pure spectrum on a screen. Name the instrument in which the conditions stated by you are fulfilled.
The sunlight can be split into its constituent colors using ______.
Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight.
The angle of deviation through a prism is minimum when
- Incident rays and emergent rays are symmetric to the prism.
- The refracted ray inside the prism becomes parallel to its base.
- The angle of incidence is equal to that of the angle of emergence.
- When the angle of emergence has doubled the angle of incidence.
Choose the correct answer from the options given below:
State True or False:
"Wavelength of red light is close to 700 nm.”
When sunlight passes through water droplets in the atmosphere it gets dispersed into its constituent colours forming a rainbow. A similar phenomenon is observed when white light passes through a prism.
Instead of sunlight, a green-coloured ray is passed through a glass prism. What will be the colour of the emergent ray?
