When a ray of light enters two specifically arranged prisms and disperese i.e. splits into characteristic colours without suffering any deviation inside the prisms(the magnitude of deviation for both the prisms is same and in opposite direction, so net deviation is zero); its called dispersion without deviation...
Deviation without Dispersion. This means an achromatic combination of two prisms in which net or resultant dispersion is zero and deviation is produced
As angle of deviation depends upon the prism material, we are in a position to put together prisms of different materials in such a way that the net outcome is such that while dispersion remains, deviations get cancelled out.
This can be done when deviation (d1) produced by first prism is equal and opposite to the deviation (d2) produced by the second prism.
The following video is about the Deviation without Dispersion which is being explained to you by a lecturer of a leading educational institute and his name is Mr. Lalit Sardana (IIT-JEE AIR 243). He has been working in the field of education since past many years and has been playing a key role in getting students into IITs and NITs. He has explained the students all the important topics like crown/ flint glass, total dispersion, achromatic combination. The students who refer to this video will be able to understand things effectively and thus score better marks in their 11th and 12th class examinations. The video is also useful for competitive exams like JEE Mains, JEE Advanced, VITEEE, MPPET, AIPMT, AFMC, BITSAT,etc.
