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NCERT Class 12 Physics Exemplar Solutions for Chapter 10 Wave Optics are designed to help Class 12 science students excel in their exams. These solutions provide detailed answers to the problems in the NCERT Exemplar book for Class 12 Physics, along with additional questions prepared by subject experts, sample papers, and previous years’ question papers.
These NCERT solutions are instrumental in helping students understand and solve important numerical problems in the chapter on Wave Optics. By working through the NCERT Exemplar questions, students can thoroughly grasp the topics and improve their chances of scoring high marks in CBSE Class 12 examinations and graduate entrance exams.
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Access Answers to the NCERT Exemplar Class 12 Physics Chapter 10 Wave Optics
Q. What is the geometric shape of the wavefront that originates when a plane wave passes through a convex lens?
(a) Converging spherical
(b) Diverging spherical
(c) Plane
(d) None of the above
Answer: (a) Converging spherical
Q. How can the fringe width increase in Young’s double-slit experiment?
(a) By decreasing the width of the slit
(b) By reducing the separation of slits
(c) By reducing the wavelength of the slits
(d) By decreasing the distance between slits and the screen
Answer: (b) By reducing the separation of slits
Q. What is the locus of all particles in a medium vibrating in the same phase called?
(a) Fringe
(b) Wavelet
(c) Wavefront
(d) None of the above
Answer: (c) Wavefront
Q. Which of the following factors does the intensity of light depend on?
(a) Frequency
(b) Wavelength
(c) Amplitude
(d) Velocity
Answer: (c) Amplitude
Also Read: NCERT Syllabus
Q. Which of the following light phenomena confirms the transverse nature of light?
(a) Refraction of light
(b) Diffraction of light
(c) Dispersion of light
(d) Polarization of light
Answer: (d) Polarization of light
Q. In a Young’s double-slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case:
(a) There shall be alternate interference patterns of red and blue
(b) There shall be an interference pattern for red distinct from that for blue
(c) There shall be no interference fringes
(d) There shall be an interference pattern for red mixing with one for blue
Answer: (c) There shall be no interference fringes
Q. Which phenomenon is used to explain the interference pattern in the Young’s double-slit experiment?
(a) Diffraction
(b) Reflection
(c) Refraction
(d) Superposition
Answer: (d) Superposition
Q. What is the phase difference for destructive interference?
(a) 0
(b) π/2
(c) π
(d) 2π
Answer: (c) π
Q. Which of the following can produce interference fringes?
(a) Two independent monochromatic sources
(b) Two coherent sources
(c) Two independent white light sources
(d) None of the above
Answer: (b) Two coherent sources
Q. What is the main factor on which the resolving power of a microscope depends?
(a) Wavelength of light
(b) Focal length of the objective
(c) Aperture of the objective
(d) Magnification
Answer: (c) Aperture of the objective
Q. What is Brewster’s angle?
(a) Angle at which light is totally internally reflected
(b) Angle at which light is partially polarized
(c) Angle at which light is fully polarized
(d) Angle at which light undergoes diffraction
Answer: (c) Angle at which light is fully polarized
Q. What is the condition for observing Fraunhoffer diffraction from a single slit?
(a) The light wavefront incident on the slit should be spherical
(b) The light wavefront incident on the slit should be cylindrical
(c) The light wavefront incident on the slit should be plane
(d) None of these
Answer: (c) The light wavefront incident on the slit should be plane
Q. What happens to the interference pattern if the wavelength of the light used is increased?
(a) The fringes become closer
(b) The fringes become farther apart
(c) The number of fringes increases
(d) The number of fringes decreases
Answer: (b) The fringes become farther apart
Read More: NCERT Syllabus Class 12
Short Answer Types
Q. What is the principle behind Young’s double slit experiment?
Answer: The principle behind Young’s double slit experiment is the interference of light waves, which demonstrates the wave nature of light.
Q. What is the condition for constructive interference in a double slit experiment?
Answer: Constructive interference occurs when the path difference between the two waves is an integer multiple of the wavelength, i.e., dsinθ=nλ.
Q. What is Brewster’s angle?
Answer: Brewster’s angle is the angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface without any reflection.
Q. Explain the concept of diffraction of light.
Answer: Diffraction of light is the bending of light waves around obstacles and the spreading of light waves when they pass through small apertures.
Q. Why does diffraction occur more prominently for sound waves than for light waves?
Answer: Diffraction occurs more prominently for sound waves because their wavelengths are comparable to the size of everyday obstacles, unlike light waves which have much shorter wavelengths.
Q. What is the significance of Huygens’ principle in wave optics?
Answer: Huygens’ principle helps in understanding the propagation of wavefronts, and it is used to derive the laws of reflection and refraction.
Q. What are coherent sources?
Answer: Coherent sources are sources of light that emit waves with a constant phase difference and the same frequency.
Q. How is polarization of light achieved?
Answer: Polarization of light can be achieved by reflection, refraction, or using polarizing filters which allow waves of only a specific polarization to pass through.
Q. What is the role of a Polaroid filter in optics?
Answer: A Polaroid filter selectively transmits light waves oscillating in a particular direction, thus producing polarized light.
Q. Describe the concept of optical path difference.
Answer: Optical path difference is the difference in the distance traveled by two light waves, considering the refractive index of the medium, which affects their phase relationship.
Q. What is the formula for the fringe width in a double slit experiment?
Answer: The fringe width β\betaβ is given by β=λDd, where λ is the wavelength of light, DDD is the distance between the slits and the screen, and ddd is the separation between the slits.
Q. Why does white light produce colored fringes in a double slit experiment?
Answer: White light produces colored fringes because it is composed of multiple wavelengths, each of which interferes constructively and destructively at different positions on the screen, producing a spectrum of colors.
Q. What is meant by the term ‘angular resolution’ of an optical instrument?
Answer: Angular resolution is the ability of an optical instrument to distinguish two close objects as separate; it is determined by the instrument’s aperture and the wavelength of light used.
Q. How does the phase difference between two waves affect the interference pattern?
Answer: The phase difference between two waves determines whether the interference will be constructive or destructive, thus affecting the brightness and positions of the fringes in the interference pattern.
More Resources for Class 12
- NCERT Exemplar Solutions for Class 12 Chemistry
- NCERT Exemplar Solutions for Class 12 Biology
- NCERT Exemplar Solutions for Class 12 Maths
Topics Discussed in the NCERT Exemplar Class 12 Physics Chapter 10 Wave Optics
- Introduction
- Huygens Principle – Statement and Experiment
- Refraction and Reflection of Plane Waves Using Huygens Principle
- Refraction of a Plane Wave
- Refraction at a Rarer Medium
- Reflection of a Plane Wave by a Plane Surface
- The Doppler Effect
- Coherent and Incoherent Addition of Waves – Interference Pattern Studies and Formula Derivation
- Interference of Light Waves and Young’s Experiment
- Diffraction
- The Single Slit
- Seeing the Single Slit Diffraction Pattern
- Resolving Power of Optical Instruments
- The Validity of Ray
- Polarisation
- Polarisation by Scattering
- Polarisation by Reflection
FAQs on NCERT Exemplar Class 12 Physics Chapter 10
What is Huygens' Principle in wave optics?
Huygens' Principle states that every point on a wavefront is a source of secondary wavelets, which spread out in all directions with the speed of light. The new wavefront is the tangent to these secondary wavelets. This principle helps in understanding the propagation of wavefronts and explains various optical phenomena such as reflection and refraction. For more detailed explanations and examples, refer to Infinity Learn's study materials.
How does Young's Double-Slit Experiment demonstrate the wave nature of light?
Young's Double-Slit Experiment shows that light exhibits interference patterns, a hallmark of wave behavior. When light passes through two closely spaced slits, it creates alternating bright and dark fringes on a screen due to constructive and destructive interference. This experiment provides strong evidence for the wave theory of light. More insights and exemplar solutions can be found on Infinity Learn's platform.
What is the significance of the diffraction of light?
Diffraction of light refers to the bending and spreading of light waves around obstacles and through openings. It is significant because it demonstrates that light behaves as a wave, causing patterns of interference. Diffraction is important in various applications, including the resolving power of optical instruments and the design of diffraction gratings. Detailed explanations and solved examples are available on Infinity Learn for further understanding.
