Exam Details

Subject Optics
Paper
Exam / Course Bachelor Degree Programme (Elective Course: Physics)
Department School of Sciences (SOS)
Organization indira gandhi national open university
Position
Exam Date December, 2016
City, State new delhi,


Question Paper

1. Attempt any three parts State Fermat's principle. Derive the laws of refraction using it. Obtain an expression for the fringe shift when a thin glass plate is introduced in the path of one of the interfering beams in a double slit interference experiment. Deduce an expression for the resolving power of a microscope. A diffraction-limited laser beam =6300 of diameter 5 mm is directed at the Earth from a space laboratory orbiting at an altitude of 600 km. How large an area would the central beam illuminate? With the help of the refractive index profile, distinguish between the step-index fibre and the gradient-index fibre. Why, in an optical fibre, should the refractive index of the core be higher than that of the cladding?

2. Attempt anyone part Define Poynting vector and state its significance.

Show that <img src='./qimages/10408-2a.jpg'>
A plate of flint glass is immersed in water. Calculate the Brewster angle for internal as well as external reflection at an interface. Take the refractive index of flint glass and water as 1.67 and 1.33, respectively.

3. Attempt any two parts: What do you understand by division of wavefront and division of amplitude Explain the formation of coherent sources in the interference experiment set-up using Lloyd's mirror.
Two waves of the same frequency and constant phase difference have intensities in the ratio 36 4. These waves are superposed and Interference fringe pattern. is obtained. Calculate the ratio of the maximum to minimum intensity. Explain the determination of the difference in the wavelengths of two nearly equal wavelengths using a Michelson interferometer.

4. Attempt anyone part Explain the concept of half period elements and show that individual Fresnel zones have approximately the same area. The seventh boundary of a zone plate has a diameter of 5 mm. Calculate its principal focal length for light of wavelength 5000 A. Write down the salient features of the double slit diffraction pattern. Derive an expression for the intensity distribution in double slit diffraction pattern.

5. Attempt any two parts What are the pre-requisites of a laser Discuss the applications of laser in communication. Explain the basic principle of holography. With the help of a diagram, describe the production of hologram. Derive an expression for the light gathering capacity of an optical fibre. Suppose the refractive indices of core and cladding of an optical fibre are 1.53 and 1.39, respectively. Calculate the numerical aperture of the fibre.


Departments

  • Centre for Corporate Education, Training & Consultancy (CCETC)
  • Centre for Corporate Education, Training & Consultancy (CCETC)
  • National Centre for Disability Studies (NCDS)
  • School of Agriculture (SOA)
  • School of Computer and Information Sciences (SOCIS)
  • School of Continuing Education (SOCE)
  • School of Education (SOE)
  • School of Engineering & Technology (SOET)
  • School of Extension and Development Studies (SOEDS)
  • School of Foreign Languages (SOFL)
  • School of Gender Development Studies(SOGDS)
  • School of Health Science (SOHS)
  • School of Humanities (SOH)
  • School of Interdisciplinary and Trans-Disciplinary Studies (SOITDS)
  • School of Journalism and New Media Studies (SOJNMS)
  • School of Law (SOL)
  • School of Management Studies (SOMS)
  • School of Performing Arts and Visual Arts (SOPVA)
  • School of Performing Arts and Visual Arts(SOPVA)
  • School of Sciences (SOS)
  • School of Social Sciences (SOSS)
  • School of Social Work (SOSW)
  • School of Tourism & Hospitality Service Sectoral SOMS (SOTHSM)
  • School of Tourism &Hospitality Service Sectoral SOMS (SOTHSSM)
  • School of Translation Studies and Training (SOTST)
  • School of Vocational Education and Training (SOVET)
  • Staff Training & Research in Distance Education (STRIDE)

Subjects

  • Astronomy and Astrophysics
  • Communication Physics
  • Electric & Magnetic Phenomena
  • Electrical Circuits and Electronics
  • Elementary Mechanics / Ocillations & Waves
  • Mathematical Methods in Physics-I/ Mathematical Methods in Physics-II
  • Mathematical Methods in Physics-III
  • Modern Physics
  • Optics
  • Physics of Solids
  • Thermodynamics & Statistical Mechanics