RAY OPTICS AND OPTICAL INSTRUMENTS-22 Quiz
Dear Readers,
JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.
Q1. Statement 1: Angle of deviation depends on the angle of prism.
Statement 2: For thin prism δ = (μ-1)A Where δ= angle of deviation μ = refractive index A = angle of prism
Statement 2: For thin prism δ = (μ-1)A Where δ= angle of deviation μ = refractive index A = angle of prism
Solution
The relation between angle of deviation δ for a thin prism, an angle of prism and refractive index of material of prism is given by δ = (μ-1)A
The relation between angle of deviation δ for a thin prism, an angle of prism and refractive index of material of prism is given by δ = (μ-1)A
Q2.Statement 1: A red object appears dark in the yellow light
Statement 2: A red colour is scattered less
Statement 2: A red colour is scattered less
Solution
A red object looks red because it reflects only red colour and absorbs all other colours present in the white light. So, when red object is seen through yellow light then it absorbs yellow colour falling on it and appears dark. Again according to Rayleigh scattering, intensity of scattered light is inversely proportional to fourth power of wavelength. Since, red colour has largest wavelength, therefore this colour will be scattered least as compared to other colours.
A red object looks red because it reflects only red colour and absorbs all other colours present in the white light. So, when red object is seen through yellow light then it absorbs yellow colour falling on it and appears dark. Again according to Rayleigh scattering, intensity of scattered light is inversely proportional to fourth power of wavelength. Since, red colour has largest wavelength, therefore this colour will be scattered least as compared to other colours.
Q3. Statement 1: The resolving power of a telescope is more if the diameter of the objective lens is more
Statement 2: Objective lens of large diameter collects more light
Statement 2: Objective lens of large diameter collects more light
Solution
(a) Resolving power =a/1.22λ
(a) Resolving power =a/1.22λ
Q4. Statement 1: Propagation of light through an optical fibre is due to total internal reflection taking place at the core-clad interface.
Statement 2: Refractive index of the material of the core of the optical fibre is greater than that of air.
Solution
Resolving power of a telescope is more if the diameter of the objective lens is more because R=a/1.22λ
where, a is diameter of the objective.
objective lens of large diameter collects more light but does not increase the resolving power of the telescope because resolving power increases when angular separation increases.
Resolving power of a telescope is more if the diameter of the objective lens is more because R=a/1.22λ
where, a is diameter of the objective.
objective lens of large diameter collects more light but does not increase the resolving power of the telescope because resolving power increases when angular separation increases.
Q5. Statement 1: The images formed by total internal reflections are much brighter than those formed by mirrors or lenses
Statement 2: There is no loss of intensity in total internal reflection
Statement 2: There is no loss of intensity in total internal reflection
Solution
In TIRE, 100% of incident light is reflected back into the same medium, and there is no loss of intensity, while in reflection from mirrors and refraction from lenses, there is always some loss of intensity. Therefore, image formed by total internal reflection are much brighter than those formed by mirrors or lenses
In TIRE, 100% of incident light is reflected back into the same medium, and there is no loss of intensity, while in reflection from mirrors and refraction from lenses, there is always some loss of intensity. Therefore, image formed by total internal reflection are much brighter than those formed by mirrors or lenses
Q6. Statement 1: There is no dispersion of light refracted through a rectangular glass slab
Statement 2: Dispersion of light is the phenomenon of splitting of a beam of white light into its constituent colours
Statement 2: Dispersion of light is the phenomenon of splitting of a beam of white light into its constituent colours
Solution
After refraction at two parallel faces of a glass slab, a ray of light emerges in a direction parallel to the direction of incidence of white light on the slab. As rays of all colours emerge in the same direction (of incidence of white light), hence there is no dispersion, but only lateral displacement
After refraction at two parallel faces of a glass slab, a ray of light emerges in a direction parallel to the direction of incidence of white light on the slab. As rays of all colours emerge in the same direction (of incidence of white light), hence there is no dispersion, but only lateral displacement
Q7. Statement 1: The speed of light in a rarer medium is greater than that in a denser medium
Statement 2: One light year equals to 9.5×10^12 km
Statement 2: One light year equals to 9.5×10^12 km
Solution
A denser medium provides more matter from which the light can scatter, so light will travel more slowly in a dense medium. A slower speed means a higher index of refraction, so n2 > n1, Also, One light year equals to 9.5×10^12km.
A denser medium provides more matter from which the light can scatter, so light will travel more slowly in a dense medium. A slower speed means a higher index of refraction, so n2 > n1, Also, One light year equals to 9.5×10^12km.
Q8. Statement 1: Dispersion of light occurs because velocity of light in a material depends upon its colour
Statement 2: The dispersive power depends only upon the material of the prism, not upon the refracting angle of the prism
Statement 2: The dispersive power depends only upon the material of the prism, not upon the refracting angle of the prism
Solution
The velocity of light in a material medium depends upon it’s colour (wavelength). If a ray of white light incident on a prism, then on emerging, the different colours are deviated through different angles Also dispersive power ω=((μ_V-μ_R))/((μ_Y-1)) i.e.,ω depends upon only μ
The velocity of light in a material medium depends upon it’s colour (wavelength). If a ray of white light incident on a prism, then on emerging, the different colours are deviated through different angles Also dispersive power ω=((μ_V-μ_R))/((μ_Y-1)) i.e.,ω depends upon only μ
Q9. Statement 1: The air bubble shines in water
Statement 2: Air bubble in water shines due to refraction of light
Statement 2: Air bubble in water shines due to refraction of light
Solution
Shining of air bubble in water is on account of total internal reflection
Shining of air bubble in water is on account of total internal reflection
Q10. Statement 1: Diamond glitters brilliantly
Statement 2: Diamond does not absorb sunlight
Statement 2: Diamond does not absorb sunlight
Solution
Diamond glitters brilliantly because light enters in diamond suffers total internal reflection.
All the light entering in it comes out of diamond after number of reflections and so light is absorbed by it
Diamond glitters brilliantly because light enters in diamond suffers total internal reflection.
All the light entering in it comes out of diamond after number of reflections and so light is absorbed by it
