Question

A glass prism is immersed in a hypothetical liquid. The curves showing the refractive index n as a function of wavelength λ for glass and liquid are as shown in fig. When a ray of white light is incident on the prism parallel to the base

This Question has multiple correct answers
Yellow ray travels without deviation
Blue ray is deviated towards the vertex
Red ray is deviated towards the base
There is no dispersion

Answer 1

Firstly find the refractive index of glass and liquid for yellow, blue and then compare them to get the appropriate answer.

Complete step by step answer: Here the diagram is shown in the figure, So first we will calculate ${{\bf{\mu }}_{glass}}\,$ and${{\bf{\mu }}_{liquid}}$ for the given colours and then compare to get the correct statement.
From the figure, we have
${{\bf{\mu }}_{glass}}\,$ ${{\bf{\mu }}_{liquid}}$ (for yellow)
⟹As ${{\bf{\mu }}_{glass}}\,$ is equal to ${{\bf{\mu }}_{liquid}}$
Both are equal, Thus there will be no deviation
OPTION A IS CORRECT
Now,
${{\bf{\mu }}_{liquid}}$ ${{\bf{\mu }}_{glass}}\,$ (for red)
⟹As ${{\bf{\mu }}_{glass}}\,$ is greater than ${{\bf{\mu }}_{liquid}}$
Thus it will be deviated towards the base
OPTION C IS CORRECT

Now,
${{\bf{\mu }}_{liquid}}$ ${{\bf{\mu }}_{glass}}\,$ (for blue)
⟹As ${{\bf{\mu }}_{liquid}}$ is greater than ${{\bf{\mu }}_{glass}}\,$.
Thus it will be deviated to
Thus, Options A,C,B are Correct

Additional Information: Refractive Index or Index of Refraction is a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density. The refractive index variable is most commonly symbolized by the letter n or n' in descriptive text and mathematical equations.

Note: The refractive index of both the liquid and the glass are the same for yellow, thus there will be no deviation. Red ray enters from a rarer to relatively denser medium, thus it will be deviated towards base and the blue ray enters from denser medium to a relatively rarer medium thus it is deviated towards the vertex.