Chapter 11 Dual Nature of Radiation and Matter

In Chapter 11 of class 12 Physics, students learn about the dual nature of radiation and matter. Students can use NCERT notes 12th Physics Chapter 11 to better understand concepts by doing text exercises. Students can follow the solutions to understand the correct approach to answering the questions in the text. Scroll down to learn more about the Chapter 11 Physics Class 12 NCERT notes.

CBSE CLASS 12th PHYSICS 11 NOTES

Points to Remember

We have provided some important points that are covered in NCERT Class 12 Physics Chapter 11 to help students in their exam preparations. Refer to the list below:

• The minimum energy required by an electron to escape from the metal surface is called the work function of the metal.

• One electron volt is the energy gained by an electron when it has been accelerated by a potential difference of 1 Volt so that 1eV = 1.602 x 10−19 J.

• There are three ways to provide energy to an electron so that it escapes the metal surface: Thermionic emission, Field emission, Photoelectric emission.

• Some photosensitive substances emit electrons called photoelectrons when they are illuminated by light by a phenomenon called the photoelectric effect. A stream of photoelectrons is called a photocurrent.

• The minimum frequency of the incident photon for the photoelectric effect to happen is called threshold frequency, and the energy of the photon at this frequency is equal to the work function of the metal.

• According to Heisenberg’s uncertainty principle, it is not possible to measure both the position and momentum of a particle at the same time exactly. The uncertainty in position (Δx) and in momentum (ΔP) are related as ΔxΔP = h/2π.

• Discovery of diffraction of electrons by C.J. Davisson and L.H. Germer lead to verification of the wave nature of electrons. In this experiment, electrons are bombarded on a metal that scatters them. The scattered electrons are collected by a collector and it is observed that the intensity of the scattered electrons is dependent on the subtle variations in the position of the collector, proving the phenomenon of diffraction in electrons.

Topics and Sub- topics

In this chapter, students learn about radiation, the duality of matter, and the work function of metals. The minimum energy required for an electron to be ejected from a metal surface is called the metal's work function. The energy (greater than the work function (φο)) required to eject electrons from the metal surface can be provided by moderate heating, application of a strong electric field, or irradiation with light of the appropriate frequency.

Before going into the details of this article, students can refer to the table below to identify all the important topics covered in this chapter.