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# NCERT Solutions for Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter

NCERT Solutions for Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter will help you get a thorough understanding of all the important concepts of the chapter. The NCERT Solutions for Chapter – Dual Nature of Radiation and Matter will provide you with a simplified way of learning. Some important topics discussed in the chapter are De Broglie wavelength, Planck’s constant, Monochromatic light, photoelectrons, photoelectric cut off voltage, work function etc. Solving NCERT questions is a must if you want to prepare well for CBSE exams in class 12.

CBSE Class 12 NCERT Physics Chapter11 – Dual Nature of Radiation and Matter comprises 1 exercise and 34 questions altogether. All of these questions revolve around the basics of various concepts from the chapter which are portrayed in forms of graphs, charts, formulas, theory, and examples and numerical. The exercise includes a mixture of theory-based and diagram-based questions.

Our subject matter experts understand the importance of this chapter for CBSE exams and hence have provided all the explanations in the answers. We have solved every numerical stepwise. You will be able to revise the chapter really quick by referring to our NCERT solutions. Our solutions will clarify all your doubts and will help you score high marks in the board examination.

## Important Topics for NCERT Solutions for Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter

Emission of electrons

This chapter will help you understand the phenomenon and methods of the emission of electrons. Free electrons in metals are not capable of escaping out of the surface normally. This happens because the metal surface acquires a positive charge and pulls the electron back towards the surface. For leaving the metal surface the electron requires a considerable amount of energy.

This minimum amount of energy which is required by the electron to escape from the metal surface is termed to be the Work Function of that metal surface. The work function of every metal majorly depends on the properties of that metal and the nature of the surface of that metal.

Methods of Electron Emission

This chapter will introduce you to the various methods with which the electrons can be emitted from a metal surface. Some of those methods are –

• Thermionic Emission – by heating the metal surface in a suitable manner, sufficient thermal energy can be produced and then this energy can be imparted to the free electrons. When this heat energy is imparted to it, then it enables the free electron to come out of the metal surface.
• Field Emission – when a very strong electric field is applied to a metal, it allows the electron to escape the metal surface as in case of a spark plug.
• Photoelectric Emission – when a light ray which has a suitable frequency, illuminates a metal surface, they tend to allow the electron to escape that metal surface and the electrons emitted are known as photoelectrons.

Stopping Potential

You will also learn about the stopping potential which depends on the frequency of the incident light and the nature of the emitter material. It is not dependent on intensity but is directly related to the maximum kinetic energy of the electron emitted.

## Exercise Discussion of NCERT Solutions for Class 12 Chapter 11 – Dual Nature of Radiation and Matter

• NCERT Solutions for Class 12 chapter 11 begin with a very simple question where the electrons present are of 30 Kv for an X-ray, and you are required to find the frequency and the minimum wavelength. You just need to place the values in the formula that has been discussed in the chapter and you will get your answer.
• Question 11.3, 11.3 and 11.4 are also similar in terms of the simplicity and formula based direct approach.
• In the further questions like question 11.9, the complexity is seen to increase in terms of the calculation and application skills.
• In question 11.10 you are required to find the threshold frequency for the photoemission of electrons. The question will provide you the value of the frequency of light and the maximum speed of the electron. Here again, you just need to recall the simple formula from the chapter and you will be able to derive your answer. Such questions are important from an exam point of view and can help you raise your score considerably in your exams.
• Question 11.14 is amongst the length questions you will encounter in the chapter. Here the wavelength of sodium is given to you and you are required to find the kinetic energy of the electron and the neutron. Here you will have to frame equations accordingly in order to obtain the solution of both the parts of this question.

## Benefits of NCERT Solutions for Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter by Instasolv

NCERT Solutions for Class 12 Physics Chapter 11 is an important chapter not only for CBSE exams but also for JEE and NEET entrance exams. At Instasolv, you get all the exercise solutions of chapter 11 that are error-free, easy to understand and include all important points of the chapter. If you have any further queries, you can send your questions to us and we will provide an instant solution to you.

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