Home
Class 12
PHYSICS
The refractive index of a material chang...

The refractive index of a material changes by 0.014 as the colour of the light changes from red to violet. A rectangular slab of height 2.00 cm made of this material is placed on a newspaper. When viewed normally in yellow light, the letters appear 1.32 cm below the top surface of the slab. Calculate the dispersive power of the material.

Text Solution

Verified by Experts

The correct Answer is:
B
Given that `: mu-mu_r=0.014`
Again` mu_r=(Real depth)/(Apparent depth)`
`=2.00/1.32=1.515`
so, dispersive power `(mu_v-mu_r)/(mu_y-1)`
`=0.014/(1.515-1)`
`=0.014/0.515=0.027`
Promotional Banner

Topper's Solved these Questions

  • DISPERSION AND SPECTRA

    HC VERMA|Exercise Objective -2|5 Videos

  • CAPACITORS

    HC VERMA|Exercise Exercise|68 Videos

  • ELECTRIC CURRENT IN CONDUCTORS

    HC VERMA|Exercise Exercises|84 Videos

Similar Questions

Explore conceptually related problems

The refractive index of a material M_1 changes by 0.014 and that of another material M_2 changes by 0.024 as the colour of the light is changed from red to violet. Two thin prisms one made of M_1 (A = 5.3^@) and other made of M_2(A = 3.7^@) are combined with their refracting angles oppositely directed. (a) Find the angular dispesion produced by the combination. (b) the prisms are now combined with their refracting angles similarly directed. Find the angular dispersion produced by the combination.

A thin prism is made of a material having refractive indices 1.61 and 1.65 for red and violet light. The dispersive power of the material is 0.07. It is found that a beam of yellow light passing through the prism suffers a minimum deviation of 4.0^@ in favourable conditions. Calculate the angle of the prism.

The focal lengths of a thin lens for red and violet light are 90.0 cm and 86.4cm respectively. Find the dispersive power of the material of the lens. Make appropriate assumptions.

An air bubble in glass slab of refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness of the slab is,

A certain material has refractive indices 1.56, 1.60 and 1.68 for red, yellow and violet light respectively. (a) Calculate the dispersive power. (b) Find the angular dispersion produced by a thin prism of angle 6° made of this material.

Read the passage and Answer the following question: In, vacuum the velocity of light radiation with different wavelength is the same. But in a material medium, the velocity of different colour radiations is not the same and they travel with different paths. Due to this, the refractive index of the medium is different for different colours. If white beam of light is incident on a glass prism, the angle of refraction for different colours is different. When Sunlight is incident on a refracting surface, then it gets split into seven coloured spectrum and emerges out. The splitting of light into its component colours is called dispersion. Sir Isaac Newton was the first to use a glass prism to obtain the spectrum of Sunlight. A glass prism is transparent medium bounded by two plane surfaces inclined at an angle. When white light is dispersed into seven colours by a prism, different colours of light bend through different angles with respect to incident ray. Out of these seven colours, red light bends the least, while violet light bends the most. So, the rays of each colour emerge along different paths and becomes distinct. Hence, we get spectrum of seven - different colours. Q. How do emergent rays appear ?