NCERT Solutions Class 12 Physics Chapter 9

NCERT Solutions Class 12 Physics Chapter 9 – Ray Optics and Optical Instruments

The NCERT Solutions Class 12 Physics Chapter 9 Ray Optics and Optical Instruments area valuable resource. Students preparing for Class 12 annual exams can find these notes on the Extramarks online platform. The important topics of this chapter, such as reflection, refraction, and dispersion of light, are well explained using pictorial representation. Using the Physics class 12 chapter 9 NCERT solutions, students can understand and obtain a firm grip of all concepts included in this chapter. Our NCERT Solutions are based on the latest guidelines for 2022-2023. 

In the Ray Optics and Optical Instruments Chapter, students will learn different phenomena of light using the ray diagrams. For example, one will study different images formed when light passes through plane and spherical reflecting and refracting surfaces. The chapter also briefly introduces the optical instruments and their working. The Extramarks NCERT Solutions Class 12 Physics Chapter 9 covers all the concepts, theories, and formulas included in this chapter. The diagrams, charts, and graphs included in the notes make learning engaging and interesting. 

The NCERT solutions class 12 Physics chapter 9 aim to help students comprehend each concept easily and attain perfect scores. Extramarks provides chapter-wise NCERT Solutions for all the subjects. Students are recommended to use the NCERT Solutions Class 9, Class 10, and Class 11 for reference to strengthen their base. Using these reference notes will help build a strong foundation for Class 12.  

Key Topics Covered In NCERT Solutions Class 12 Physics Chapter 9

The Extramarks NCERT Solutions Class 12 Physics Chapter 9 provides apt information and knowledge. It is an important resource for the preparation of board exams along with Entrance exams like NEET, JEE (Main and Advanced).  

These notes are prepared by the subject elites at Extramarks to give perfect knowledge of complex topics and include all minute detail. The following topics are covered in the NCERT Solutions Class 12 Physics Chapter 9. 

9.1 Introduction

Chapter 9 Physics class 12 is based on the different characteristics of light as it passes through media, namely, the convex lens, concave lens, spherical mirrors, and prism. The chapter begins with a thorough discussion of light processes like reflection, refraction, and dispersion using several ray diagrams. It then describes some natural phenomena that occur due to sunlight, such as formation of rainbow and scattering of light. Students also gain an insight into the working and construction of the human eye and other optical instruments. 

The main features of the chapter are

• Rectilinear Propagation of Light
• Characteristics of light
• Laws of Refraction
• Laws of Reflection
• Human Eye

9.2 Reflection Of Light By Spherical Mirrors

This section helps students strengthen their understanding of concepts related to spherical mirrors. Concepts like Sign convention, Focal length of Spherical mirror, and paraxial rays have also been discussed. The NCERT Solutions Class 12 Physics Chapter 9 also gives a step-by-step explanation about the focal length (f) of the spherical mirror with the help of the formula, f = R2, where R= Radius of curvature. Students can get a clear idea of the mirror formula, magnification and lateral inversion included in this section. 

9.3 Refraction

This section of class 12 Physics chapter 9 NCERT solutions gives brief information about the refraction of light through a curved surface. Students can comprehend topics like refractive index, critical angle, and relative refractive index. Cauchy’s formula helps students learn the relation between the refractive index of a medium () and the wavelength of light (). The causes and laws of refraction (Snell’s Law) is an important concept in this section of the NCERT Solutions Class 12 Physics Chapter 9. 

9.4 Total Internal Reflection

In this section of Chapter 9, students learn about Total Internal Reflection (TIR) in nature and its applications. Concepts like Double refraction and Single refraction from a plane surface and the relation between object distance and image distance have been explained lucidly. This section also includes knowledge about the formation of Mirages, Diamonds, Prisms, and Optical fibres based on TIR. 

Students should gain an in-depth understanding of these concepts to solve questions of any difficulty level with ease. 

9.5 Refraction At Spherical Surfaces And By Lenses

This section is bifurcated into four parts: Refraction at a Spherical Surface, Refraction by a Lens, Power of a Lens, and Combination of Thin Lenses in Contact. With the help of the NCERT Solutions Class 12 Physics Chapter 9, students will learn to differentiate between a thin lens and a standard lens. 

Some of the main formulas explained in this section are as follows:

• Lens Formula
• Mirror Formula
• Lens makers formula
• Power of a Lens
• The focal length of lens Combination
• Power of Lens Combination
• Linear magnification
• The focal length of the convex lens using the displacement method 

The NCERT Solutions Class 12 Physics Chapter 9 includes the derivation of the equations that helps students get an in-depth understanding of these concepts. 

9.6 Refraction Through A Prism

In this section of chapter 9 Physics class 12, students learn about the prism. It covers various features and the importance of a prism. Topics like Angle of Deviation and Prism formula are very well explained with the help of the prism diagram in the NCERT Solutions Class 12 Physics Chapter 9. Moreover, students can synopsize with the help of the simple explanation given about the condition of no emergence and dispersive power along with the equations. 

9.7 Dispersion By A Prism

Based on the above topic, students learn the theory of dispersion and deviation of light by a prism. In NCERT Solutions Class 12 Physics Chapter 9, students can acquire accurate information of the angular dispersion and dispersive power within this section. 

It is an important topic from the Physics class 12 chapter 9 NCERT solutions and has been asked several times in CBSE class 12 board exams. 

9.8 Some Natural Phenomena Due To Sunlight

A brief discussion on the scattering of light, Rainbow, Blue Sky, and the reddish appearance of the sun in full moon near horizon has been given in NCERT Solutions Class 12 Physics Chapter 9. Furthermore, the Rayleigh’slaw of scattering is explained as the relationship between the amount of scattering and the wavelength of light. 

9.9 Optical Instruments

The working and construction of Optical Instruments such as the Human Eye, Telescope, and Microscope have been explained with the help of diagrams. In addition, NCERT Solutions Class 12 Physics Chapter 9 also includes detailed explanations of eye defects such as myopia or near-sightedness, Hypermetropia or far-sightedness, Astigmatism, Colour Blindness, and Cataract using the ray diagrams. This segment will help the students to understand the ray diagrams and magnifying power of the Telescope and simple Microscope. 

Students are advised to use the chapter 9 Physics class 12 NCERT solutions to significantly speed up their learning process.

List of NCERT Solutions Class 12 Physics Chapter 9 Exercise & Answer Solutions

Extramarks provides study materials like the NCERT Solutions Class 12 Physics Chapter 9, CBSE previous year question papers, sample papers, NCERT Solutions from Class 1 to 12 for the benefit of the students. These notes ensure a thorough understanding of all essential topics included in the chapter. With the help of these notes, students can understand and revise the formulas, equations, and ray diagrams quickly to solve all questions based on them. Refer to the below content to get more details on NCERT Solutions Class 12 Physics Chapter 9: 

Students can also click on the below links to get access to the NCERT Solutions based on new guidelines:

• NCERT Solutions Class 1
• NCERT Solutions Class 2
• NCERT Solutions Class 3
• NCERT Solutions Class 4
• NCERT Solutions Class 5
• NCERT Solutions Class 6
• NCERT Solutions Class 7
• NCERT Solutions Class 8
• NCERT Solutions Class 9
• NCERT Solutions Class 10
• NCERT Solutions Class 11
• NCERT Solutions Class 12

NCERT Exemplar Class 12 Physics

Students can start their preparation for Class 12 Physics Chapter 9 using the NCERT Exemplar Solutions available to the Extramarks platform. They can find solutions to all subjective, objective, in-text, and exercise questions included in the NCERT books. In addition, there are also many extra questions based on important topics mentioned in the  NCERT Solutions Class 12 Physics Chapter 9. With the help of these notes, students can prepare for the CBSE school level exams and many other national level entrance exams. 

Extramarks aims to help students to achieve good results. Hence we offer study materials curated by a team of skilled subject experts in such a way as to help students tackle even the most complex questions easily and accurately. 

Key Features of NCERT Solutions Class 12 Physics Chapter 9

The key features of NCERT Solutions Class 12 Physics Chapter 9 include

• The solutions include all important concepts, formulas, equations, and solved examples in one place. 
• Students will learn to analyze themselves based on their performance and know which topic they should practice more.
• Experts curate the NCERT Solutions Class 12 Physics Chapter 9 based on the latest NCERT textbooks. 
• It is considered the one-stop solution for students’ every need. 
• The Notes help students clear any doubts and understand each concept well to attempt questions based on them easily.