S.S. Krotov Optics Solutions (Chapter 4)

SS Krotov Science for Everyone – Problems in Physics Solutions for Chapter 4 ‘Optics’ prove to be computationally efficient if you are a JEE aspirant. These solutions are prepared by the best subject matter experts at Instasolv and would improve your problem-solving skills. This chapter mainly focuses on various principles of optics ray diagrams and symmetrical annular diaphragm. There are aptitude questions based on laws of reflection, polarization, Snell’s law to solve different problems based on the index of reflection, angle of incident and reflected rays, converging or diverging lenses, focal point and focal length of lenses in the telescope.

SS Krotov Physics solutions for Optics contains a total of 20 questions. Our subject experts have answered all the questions from a theoretical point of view that would act as an additional guide to achieving success in entrance exams like IIT JEE. You must understand the process of reflection and refraction of light and how an image is formed on plane mirrors, spherical mirrors and spherical lenses.

SS Krotov Solutions discuss the concepts of refractive index, focal length and illumination clearly and interestingly for you. Our well-resolved solutions to SS Krotov Optics include a thorough description of every question. You must refer to these solutions to remove all your doubts regarding the higher-level concepts of optics.

Important topics for SS Krotov Science for Everyone – Problems in Physics Solutions Chapter 4: Optics

In this chapter, you will use the law on refraction to examine the properties of lenses and how they shape images. Lenses are used in a broad range of optical devices, varying from plain magnifying glass to an eye, to a film zoom lens. 

Image Formation by Lenses

  • The term lens is derived from the Latin word for lentil bean, the form of which is identical to the convex lens.
  • The axis is described as the normal line to the centre of the lens.
  • Such a lens is known to be a converging (or convex) lens with converging effects on light rays. The enlarged image of the course of a single ray through the lens is seen to demonstrate how the ray shifts direction, both when it approaches and when it exits the lens. 
  • Because the refraction index of the lens is larger than that of the surface, the angle travels towards the perpendicular when it approaches and away from the perpendicular as it exists. (This shall comply with the Law of Refraction.)
  • Due to the shape of the lens, the light at both surfaces is bent towards the axis. The point at which the rays pass through is defined as the focal point F of the lens.
  • The length from the centre of the lens to its focal point is known as the focal length of the lens f.

  • Light rays leaving the converging lens parallel to the pole concentrate at the focal point F.

  • The power P of the lens is known as the reverse of its focal length. In the form of an equation, this is Here f is focal length.

P =1/f

  • The power of the P lens has the diopter unit (D) provided that the focal length is provided in meters. 

1D = 1/m or 1m-1

  • It is a term relating to the impact of optical instruments on a light. Optometrists recommend common spectacles and contact lenses in diopter systems.
  • The concave lens is indeed a diverging lens since it allows light rays to move (diverge) further from its axis.
  • Under the given scenario down below, the lens has been moulded so that all light rays trying to enter it parallel to its axis appear to originate from the same point, F, defined as the focal point of the diverging lens. The length from the centre of the lens to the focal point is once again called the focal length of the lens f. Keep in mind that the focal length and power of the converging lens are defined as negative.

  • The image wherein light rays from one point of the object directly reach the origin of the image and maybe reflected on a screen, a frame of film or the retina of the eye is considered a real image.

  • From the above diagram :
  • Image (a): A real image of a human is being projected onto a screen.
  • Image (b): The diverging nature of the different surfaces that constitute the eye results in the reflection of an image on the retina of a human eye.
  • To obtain numeric data, we use a couple of equations that can be obtained from the mathematical analysis of the rasterization of thin lenses. thin lens equations are written as,

1/do + 1/di = 1/f

hi /ho =  – di / do = m

Here, do is the distance of the object, di is image distance, ho and hi are the heights of the image and object respectively and m is magnification.

  • Thin lens calculations are usually relevant to any conditions concerning thinner lenses.
  • An image that is on the similar side of the lens as an entity that can never be projected on a  screen is considered a virtual picture.
  • The length of the image from the centre of the lens is called the image distance.
  • The virtual image is the precise reflection of the real person or entity such that it includes the following characteristics :
  • The image is just a similar size as the initial object.
  • It’s vertical.
  • The distance between both the individual and the mirror is called the distance between the object.
  • The refractive index of a medium is given the symbol n. It is calculated by dividing the speed of light in a vacuum by the speed of light in a medium:

  • Snell’s Law of Refraction: Given below is an image of how a ray of light refracts as it moves from a vacuum to a medium (glass).

  • The formula of snell’s law:

          Sin θi / Sin  θr  = n

  • The formula of Snell’s Law in two Mediums:

Here, n is an index of reflection, n1 is the incident medium and n2 is the refractive medium.

  • Telescopes and Binoculars: In the optical telescope, the objective lens creates an upside-down image that is further magnified by the eyepiece mirror.

This is the same range from the surface of the mirror as the person or object from the mirror.

The symmetrical annular diaphragm given below consumes beams across all virtual references to the very same extent. The light of the ring on the panel would reduce evenly.

Exercise Discussion for SS Krotov Science for Everyone – Problems in Physics Solutions Chapter 4: Optics

  • SS Krotov Optics Solutions have 20 questions. This chapter includes two types of questionnaires; analytical and problem-solving.
  • Problem-solving questions mainly focus on the application of different formulas of a thin lens, centripetal acceleration, angle of refraction, telescope, diverging lens formula. Some problem is based on the determination of the distance between the given points at which rays intersect
  • Theoretical-based questions include a basic understanding of concepts based on the symmetrical annular diaphragm, gas pressure distribution near the axis of the vessel, diverging and converging lenses, the law of refraction, power of lenses, and angle of incidence.

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  • SS Krotov Physics solutions for Optics has several problems coupled with comprehensive answers and definitions, making it a convenience for the preparation of competitive examinations.
  • Our SS Krotov Solutions not only give you a deeper understanding of the concepts but will also significantly improve your confidence in physics throughout the preparations.
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