Question
Question: Which of the two prisms, A made of crown glass and B made of flint glass, deviates a ray of light mo...
Which of the two prisms, A made of crown glass and B made of flint glass, deviates a ray of light more?
(A) A
(B) B
(C) Both deviate same
(D) Can't say
Solution
Hint
Deviation of a ray of light through a prism ray is the angle between the entered ray and emerging ray through the faces of prism. It depends on the medium with which prism is made. Higher the refractive index of material of prism, higher is the deviation of ray.
Complete step by step answer
When a ray of light enters a prism, it gets refracted and while leaving it gets refracted again and the resultant ray is known as an emerging ray. This phenomenon of changing the path of a ray while passing through a prism is known as deviation. The deviation of the ray is the angle between the entered ray and emerging ray. This deviation depends on the refractive index of the material through which the prism is made. The refractive index of flint glass is 1.62 whereas the refractive index of crown glass is 1.52. As the refractive index of flint glass is more it will bend the emerging ray more than that by crown glass, which results in a larger deviation angle. So, the prism made of flint glass deviates the ray of light more.
So, the correct answer is (B).
Note
The angle of deviation not only depends upon the material through which it is made but also upon the angle of incidence. Dispersion is a phenomenon where white light is split into various components while passing through a prism.