Explain the cause of dispersion of white light through a prism.
Answers
State the cause of dispersion, when white light enters a glass prism. ... Each colour travels at its own speed inside a prism.Due to this 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 the most.
Answer:
dispersion of white light by prism :-- when a narrow beam of light is incident on a prism, the emergent Beam is not only deviated, but at the same time splits up into a coloured band of seven colours. This phenomena is called dispersion of light. The 7 colours of band are violet, Indigo,green,yellow, orange and red. Violet colour deviates through maximum angle and red colour deviates through the minimum angle.Red,green and blue are called primary colours or basic colours. Mixing of colours:- 1. red + green+ blue is equal to white 2. red + blue is equal to Magenta 3. blue + green is equal to peacock blue( or Cyan).4. red + green is equal to yellow 5. If all the colours of white light are reflected back from the object, then it appears white.6. And if all the colours of white light is absorbed by an object, then it appears black.7.Polarisation is the only phenomena which proves that light is a transverse wave. 8. The layer of kerosene oil over water surface appear coloured in the presence of sunlight due to proper interference of light. PRISM :--- IT IS A UNIFORM TRANSPARENT REFRACTING MEDIUM BOUNDED BY TWO PLANE SURFACES INCLINED AT CERTAIN ANGLE.