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NCERT Solutions for Class 12 Physics Chapter 10 - Wave Optics - PDF Download

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NCERT Solutions for Wave Optics Class 12 are now available for you, who want to get the best preparation for the exam. All the questions from this chapter 10 along with the extra questions are solved. Expert Physics teachers solved these questions in a very simple language. To secure more marks in Physics, Download NCERT Solutions Class 12 Physics Wave Optics PDF which is available in the free PDF format.

In chapter 10 wave optics, you will learn about Huygens' principle, refraction and reflection of plane waves, coherent and incoherent waves and each topic is explained with experiment and examples. After completing the topics then you will get exercise to solve.

Topics Covered in Class 12 Physics Chapter 10 Wave Optics

Section Number

Topic

10.1

Introduction

10.2

Huygens’ Principle

10.3

Refraction and Reflection of Plane Waves Using Huygens Principle

10.3.1

Refraction of a Plane Wave

10.3.2

Refraction at a Rarer Medium

10.3.3

Reflection of a Plane Wave by a Plane Surface

10.4

Coherent and Incoherent Addition of Waves

10.5

Interference of Light Waves and Young’s Experiment

10.6

Diffraction

10.6.1

The Single Slit

10.6.2

Seeing the Single Slit Diffraction Pattern

10.6.3

Resolving Power of Optical Instruments

10.6.4

The Validity of Ray Optics

10.7

Polarisation

Huygens’ Principle

When we throw a small stone on a calm pool of water, waves spread out from the point of impact. Each point on the surface starts oscillating with time. At any point of time, a photograph of the surface would show circular rings on which the disturbance is maximum. It is very clear, all points on such a circle are oscillating in phase because they all are at the same distance from the source. Such a locus of points, which oscillate in phase, is known as wavefront. Huygens' principle is also known as Huygens-Fresnel principle, a statement that all points of a wave front of sound in a transmitting medium or of light in a vacuum or transparent medium may be regarded as new sources of wavelets that expand in every direction at a rate depending on their velocities.

Refraction and Reflection of Plane Waves Using Huygens Principle

Huygens's principle applied to a plane wave front travelling from one medium to another medium, where the speed of the wave is less. Huygens principle says that every point on a wavefront is in itself the source of spherical wavelets.

Refraction of a Plane Wave

The bending of light waves of light waves is called refraction. The amount of refraction depends on two things: one is the change in the speed of light and another one is the angle at which the waves are bending. Snell's law states that the relationship between angles of incidence and refraction, and the refractive index of each medium.

Refraction at a Rarer Medium

When a wave travels from denser to rarer medium it bends away from the normal and angle of refraction is always greater than angle of incident. When a wave travels from rarer to denser medium the refracted ray bends towards the normal and the angle of refraction is less than the angle of incidence.

Reflection of a Plane Wave by a Plane Surface

As per the Snell's law the ratio of sine of angle of incidence to the sine of angle of refraction is equal to the ratio of refractive index of second medium to the first medium. Huygen's principle states that each point on a wavefront is a source of secondary waves, which add up to later wavefronts.

Coherent and Incoherent Addition of Waves

Coherent waves are those waves which have the same frequency and zero or constant phase difference. Incoherent waves have random phase differences and frequencies. Addition of waves deal with the interference patterns that are created by the superposition of two waves.

Interference of Light Waves and Young’s Experiment

Young's double slit experiment uses two coherent sources of light s1 and s2 which are placed at a small distance apart. Usually, only those magnitudes greater than the wavelength of light are used. Young's double slit experiment helped in understanding the wave theory of light.

Diffraction

Diffraction is the slight changes in direction of light as it passes around the edge of an object. The amount of bending of light depends on the relative size of the wavelength of light to the size of the opening. If the opening is much larger than the light's wavelength, the bending will be almost unseen.

Polarisation

Polarization or polarisation is a property of transverse waves which specifies the geometrical orientation of the oscillations.Transverse wave is the direction of the oscillation is perpendicular to the direction of motion of the wave. 

Benefits of NCERT Solutions for Class 12 Physics Chapter 10 Wave Optics -

Some important benefits that you would get with the help of NCERT Solutions of Wave Optics Class 12 are given below

  • All of these solutions are written while keeping your exam guidelines in mind.

  • NCERT Solution of Wave Optics Class 12th is written in such an easy way that every student can understand it.

  • These solutions are available in PDF format and you can download this at any time and access them.

  • The given solution is easily accessible offline for future use, so you can easily practice it before the exam. 

  • Physics Ch 10 Class 12 NCERT Solutions encourages you to develop your answering skills. Students are given point-wise solutions.

Frequently Asked Question

Question 1 : What is Huygens’ Principle?

Answer : When we throw a small stone on a calm pool of water, waves spread out from the point of impact. Every point on the surface starts oscillating with time. At any point of time, a photograph of the surface would show circular rings on which the disturbance is maximum. It is very clear, all points on such a circle are oscillating in phase because they all are at the same distance from the source. Such a locus of points, which oscillate in phase, is known as wavefront. Huygens' principle is also known as Huygens-Fresnel principle, a statement that all points of a wave front of sound in a transmitting medium or of light in a vacuum or transparent medium may be regarded as new sources of wavelets that expand in every direction at a rate depending on their velocities.

Question 2 : What is Diffraction

Answer : Diffraction is the slight changes in direction of light as it passes around the edge of an object. The amount of bending of light depends on the relative size of the wavelength of light to the size of the opening. If the opening is much larger than the light's wavelength, the bending will be almost unseen.