Download Feedback Form SET V (Units 7,14,15)

PHE - 09
SET-V
ASSIGNMENT BOOKLET
Bachelor’s Degree Programme
OPTICS (PHE-09)
IMPORTANT INSTRUCTIONS

Please put the completed Assignment Response
(to Sections I, II, III and IV) in the stamped envelope
enclosed and MAIL IT TO US.


Do not submit this Assignment at your Study Centre.
Please read page 2 of this booklet carefully before
doing the Assignment.
School of Sciences
Indira Gandhi National Open University
Maidan Garhi, New Delhi – 110068
2003
Dear Student,
We hope you are familiar with the system of evaluation being followed for B.Sc. in IGNOU. As
you are aware, a weightage of 30 percent has been earmarked for continuous evaluation, which
would consist of two tutor-marked assignments for this course.
This is a special assignment. Through it we would like to get your feedback on Units 7, 14
and 15 of the course while you are studying it.
This assignment has four sections. Sections II, III and IV, taken together, is equivalent to two
tutor-marked assignments (TMA-1 and TMA-2) for the course. Please fill in the answers to the
questions in Sections I and II on the pages given in the assignment itself with all honesty and
integrity. Do not give incorrect information just to please us. Your answers should be based on
your own experiences  good or bad.
We will like you to emphasize that your feedback will help us improve the course materials.
We will also be able to provide you better support and advice for your studies.
Read the questions in Section II before studying the Units 7, 14 and 15. In this Section, you
have to answer

Questions 3(i) to 3(x) while studying Unit 7, Questions 4(i) to 4(x) while studying Unit 14,
and Questions 5(i) to 5(x) while studying Unit 15.

Questions 6 and 7 after studying all the three Units (Units 7, 14 and 15).
You must respond to Sections I and II. Without these responses, your assignment will be
regarded as incomplete and your assignment marks will not be entered in your record.
For writing your answers to Sections III and IV, use separate foolscap size writing paper
(but not of very thin variety). Be precise. Write units at each step of your calculations. Take care
of significant digits in your work. Recheck your work before submitting it.
Please keep a copy of your assignment with you for the sake of record.
Please put the completed Assignment (Sections I, II, III and IV) in the
stamped envelope enclosed and mail it to us within 12 weeks of receiving
this Assignment. Do not submit it at the Study Centre.
Thank You.
(S.R. JHA)
Course Coordinator, PHE–09
School of Sciences (Block-7),
IGNOU, Maidan Garhi,
New Delhi-110 068
2
TUTOR MARKED ASSIGNMENT1 & 2
Optics (PHE-09)
Course Code: PHE-09
Assignment Code: PHE-09/TMA-1&2/2003
Maximum marks: 200
Section I : General Information
Note: This section is compulsory. Fill your responses on these very pages. Put a tick mark ( ) on
the option that is correct, wherever necessary.
1.
2.
i) Name : ………………………
ii) Date of birth : ………………
iv) Enrolment Number:
v) Study Centre Code :
iii) Gender : Male / Female
vi) Name of Study Centre : ……………………………..
…………………………….
Do you have access to Internet? Yes, at home / Yes, at a friend’s home / Yes, at cybercafe / Yes,
at study centre / No
If yes, write your e-mail address: …………………………………………………………………...
If not, what is the reason : Not accessible / Expensive / Not comfortable with Computers / Any
other ……………………………………………………………………………………………….
….………..……………….
3.
In which year did you complete your +2 or equivalent ?
4.
i) Did you study Mathematics at +2 ?
Yes / No
ii) Percentage of marks obtained in +2 :
….………..……………………….
iii) Percentage of marks obtained in Physics at +2 : . ….………..……………………...
5.
Rate your proficiency in English : very good / good / fair / average / not so good
6.
Are you employed ?
Yes / No
If employed, tell us (in about 2-3 lines) about the nature of your job and the position in which you
are employed ……………………………………………………………………………………….
…………………………………………………………….…………………………………………
…………………………………………………………….…………………………………………
7.
Are you planning to do B.Sc. (major) in any discipline?
Yes / No
If yes, which discipline?
Physics / Chemistry / Mathematics / Botany / Zoology
8.
Do you want to go for M.Sc. ( Physics) ?
Yes / No
If not, what would you like to do after B.Sc.? How would a B.Sc. degree be helpful to you?
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
9.
What is your purpose of studying Physics electives in B.Sc.? …………………………………….
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
3
10.
What is your purpose of studying this course (Optics; PHE-09)?…………………………………..
…………………………………………………………….…………………………………………
…………………………………………………………….…………………………………………
11.
i)
Are you doing B.Sc. at IGNOU: as a first choice / because you had no other option?
ii) Tell us (in 2-3 lines) why you chose to do your B.Sc. from IGNOU? ………………………...
………………………………………………………………………………………………….
………………………………………………………………………………………………….
Section II : General Feedback
(30 marks)
Note: This section is compulsory. Fill your responses on these very pages . Put a tick mark ( ) on
the relevant option, wherever necessary. Answer Questions 3(i) to 3(x) while studying Unit 7,
Questions 4(i) to 4(x) while studying Unit 14, and Questions 5(i) to 5(x) while studying Unit 15 and
Questions 6 and 7 after studying all the three Units (Units 7, 14 and 15).
1.
How much time (in hours or days) are you usually able to devote for studying this course?
i) a) On a daily basis : less than an hour / 1 to 2 hours / 2 to 3 hours / More than 3 hours
b) On a weekly basis : once a week / 2 to 3 times a week / 4 to 6 times a week / daily
ii) When do you normally study? (Answer in 1-2 lines). …………………………………….
……………………………………………………………………………………………...
iii) Do you plan to study one month before the term-end exam? If yes, please tell us why
(in 1-2 lines)
…………………………………………………………………………………………….……
…………………………………………………………………………………………….……
iv) What kind of support do you get from your family for your studies? Answer in 2 to 3 lines.
…………………………………………………………………………………………….………….
…………………………………………………………………………………………….………….
2.
i)
Did you study the course introduction and block introduction before studying
the units?
Yes / No
If yes, do you have any suggestions about their content, length, language, etc?
………………………………………………………………………………….………………
………………………………………………………………………………….………………
………………………………………………………………………………….………………
ii) Have you studied following courses before studying this course:
a) PHE-02:
Yes / No ;
b) PHE-04:
Yes / No ;
4
c) PHE-07:
Yes / No
3.
i)
Did you read the introduction and objectives of Unit 7 before studying it?
ii) Are the introduction and objectives of Unit 7 clear to you?
If not, state the difficulty :
Yes / No
Yes / No
……..………………………………………….……………………………………………………………………………………………………………..
……..………………………………………….……………………………………………………………………………………………………………..
iii) Section wise Feedback : Answer this question while studying each section of the Unit or immediately afterwards.
Note : Please tell us about your difficulties in studying each section of Unit 7. To describe your response, you may select the appropriate words from
among the following : not clear, not sufficient, difficult, not relevant, not interesting. If you wish, you can use any other words. For example, if
you feel that the language used in Sec. 7.2 is difficult and not clear, you should write the words ‘difficult, not clear’ at *. In the last column, you have to tell
the approximate time you have taken to study each section.
While answering Question 3(iv), you have to tell us what is not clear or what more is required etc. in detail.
Section
7.2
Explanation of
Examples
Language
Mathematics
Technical terms/
Figures/
Solutions to
Time taken to study
Concepts
given
used
used
definitions
Tables
SAQs and
terminal
questions
the section (hours)
*
7.2.4
7.2.5
7.3
7.7
5
3.
iv) If you have filled in words like 'not clear / difficult / not sufficient / not interesting', etc. in
any of the rows and columns in Question 3(iii), please mention what is not clear about each
part. Use additional pages if need be.
v)
What (e.g., explanation, diagram, examples, definitions, etc.) would you like to be added or
deleted in each of the sections to make it easier to study? Use additional pages if your
answer is long.
vi) Do you need more guidance or help on how to study Unit 7?
Yes / No
If yes, can you tell us what kind of guidance or help you
require?……………………………...…………………………………………………………
………………………………….……………………………………………………………..
vii) Put a tick mark on the correct response.
a)
b)
c)
d)
The level of the contents was as I expected: Yes / No, it was too high / No, it was lower.
The topics, concepts covered were interesting, and informative:
Yes / No
The mathematics used was as I expected:
Yes / No, it was difficult / No, it was easy
I would have preferred a non-mathematical explanation:
Yes / No
viii) Which objective (s) of the unit have you not achieved after studying it?……………………..
………………………………………………………………………………………………….
ix) What did you like best about this unit?………………………………………………………...
………………………………………………………………………………………………….
x)
What did you not like about this unit? ………………………………………………………...
………………………………………………………………………………………………….
6
4.
i)
Did you read the introduction and objectives of Unit 14 before studying it? Yes / No
ii) Are the introduction and objectives of Unit 14 clear to you?
If not, state the difficulty :
Yes / No
……..………………………………………….……………………………………………………………………………………………………………..
……..………………………………………….……………………………………………………………………………………………………………..
iii) Section wise Feedback : Answer this question while studying each section of the Unit or immediately afterwards.
Note : Please tell us about your difficulties in studying each section of Unit 14. To describe your response, you may select the appropriate words from
among the following : not clear, not sufficient, difficult, not relevant, not interesting. If you wish, you can use any other words. For example, if
you feel that the language used in Sec. 14.2 is difficult and not clear, you should write the words ‘difficult, not clear’ at *. In the last column, you have to tell
the approximate time you have taken to study each section.
While answering Question 4(iv), you have to tell us what is not clear or what more is required etc. in detail.
Section
14.2
Explanation of
Examples
Language
Mathematics
Technical terms/
Figures/
Solutions to
Time taken to study
Concepts
given
used
used
definitions
Tables
SAQs and
terminal
questions
the section (hours)
*
14.3
14.3.1
14.3.2
14.4
7
4.
iv) If you have filled in words like 'not clear / difficult / not sufficient / not interesting', etc. in
any of the rows and columns in Question 4(iii), please mention what is not clear about each
part. Use additional pages if need be.
v)
What (e.g., explanation, diagram, examples, definitions, etc.) would you like to be added or
deleted in each of the sections to make it easier to study? Use additional pages if your
answer is long.
vi) Do you need more guidance or help on how to study Unit 14?
Yes / No
If yes, can you tell us what kind of guidance or help you
require?……………………………...…………………………………………………………
………………………………….……………………………………………………………..
vii) Put a tick mark on the correct response.
a)
b)
c)
d)
The level of the contents was as I expected: Yes / No, it was too high / No, it was lower.
The topics, concepts covered were interesting, and informative:
Yes / No
The mathematics used was as I expected:
Yes / No, it was difficult / No, it was easy
I would have preferred a non-mathematical explanation:
Yes / No
viii) Which objective (s) of the unit have you not achieved after studying it?……………………..
………………………………………………………………………………………………….
ix) What did you like best about this unit?………………………………………………………...
………………………………………………………………………………………………….
x)
What did you not like about this unit? ………………………………………………………...
………………………………………………………………………………………………….
8
5.
i)
Did you read the introduction and objectives of Unit 15 before studying it? Yes / No
ii) Are the introduction and objectives of Unit 15 clear to you?
If not, state the difficulty :
Yes / No
……..………………………………………….……………………………………………………………………………………………………………..
……..………………………………………….……………………………………………………………………………………………………………..
iii) Section wise Feedback : Answer this question while studying each section of the Unit or immediately afterwards.
Note : Please tell us about your difficulties in studying each section of Unit 15. To describe your response, you may select the appropriate words from
among the following : not clear, not sufficient, difficult, not relevant, not interesting. If you wish, you can use any other words. For example, if
you feel that the language used in Sec. 15.2 is difficult and not clear, you should write the words ‘difficult, not clear’ at *. In the last column, you have to tell
the approximate time you have taken to study each section.
While answering Question 5 (iv), you have to tell us what is not clear or what more is required etc. in detail.
Section
15.2
Explanation of
Examples
Language
Mathematics
Technical terms/
Figures/
Solutions to
Time taken to study
Concepts
given
used
used
definitions
Tables
SAQs and
terminal
questions
the section (hours)
*
15.3
9
5.
iv) If you have filled in words like 'not clear / difficult / not sufficient / not interesting', etc. in
any of the rows and columns in Question 5(iii), please mention what is not clear about each
part. Use additional pages if need be.
v)
What (e.g., explanation, diagram, examples, definitions, etc.) would you like to be added or
deleted in each of the sections to make it easier to study? Use additional pages if your
answer is long.
vi) Do you need more guidance or help on how to study Unit 15?
Yes / No
If yes, can you tell us what kind of guidance or help you
require?……………………………...…………………………………………………………
………………………………….……………………………………………………………..
vii) Put a tick mark on the correct response.
a)
b)
c)
d)
The level of the contents was as I expected: Yes / No, it was too high / No, it was lower.
The topics, concepts covered were interesting, and informative:
Yes / No
The mathematics used was as I expected:
Yes / No, it was difficult / No, it was easy
I would have preferred a non-mathematical explanation:
Yes / No
viii) Which objective (s) of the unit have you not achieved after studying it?……………………..
………………………………………………………………………………………………….
ix) What did you like best about this unit?………………………………………………………...
………………………………………………………………………………………………….
x)
What did you not like about this unit? ………………………………………………………...
………………………………………………………………………………………………….
10
6. i) How did you study the Units? (Tick the relevant option)

Usually on your own
Usually in a group with friends

Read everything given in Units and
then revised main points
Read only major points given in
bold, italics or boxes, etc.

Took notes on important points in Did not take notes but underlined text
margin or in separate note books

Worked out all mathematical steps
and worked through solved examples
on your own

Solved SAQs and Terminal questions Looked immediately at the answers Looked at the answers
given in the end
if you found solving
on your own as you came to them
any question difficult

Consulted
Optics


Did not take notes
Skipped mathematical steps but Skipped both
worked through solved examples
mathematical steps
and solved examples
not
consult
on Consulted notes or books available in Did
the market
anything other than the
IGNOU study material
Noted down difficult points in the Preferred to be lectured at the study
margin for clarification at the study centre about various topics in the
Unit
centre
standard
text-books
Read the summary to quickly revise the Skipped the summary
Unit
ii) Is there anything else you may like to say about how you studied the Units?
……………………………………………………………………………………………………..
………………………………………………………………………………………………….….
iii) How did you find the Units in terms of amount of work/time required?
a) Unit 7: Very light / Fairly light / About right / Fairly heavy / Very heavy
b) Unit 14: Very light / Fairly light / About right / Fairly heavy / Very heavy
c) Unit 15: Very light / Fairly light / About right / Fairly heavy / Very heavy
7. i)
How did you deal with your difficulties in the Units?
Asked the counsellor / consulted fellow students / tried to understand on your own but gave up
if you could not / took help from a tutor nearby / Any other ……………………………………
……………………………………………………………………………………………………
ii) Did you attend the counselling sessions?
Yes / No
Is the number of counselling sessions enough?
Yes / No
If not, what should it be? ………………………………………………………………………….
How many counselling sessions did you attend? …………………………………………………
If not, please tell us why you did not/could not attend ……………………………………………
……………………………………………………………………………………………………..
11
iii) How do you want your counselling sessions to be organised?
You want to be lectured on various topics / you want your difficulties to be solved / you want
help with your assignment / you want guidance on how to study the course /any other
………………………………………………………………………………………………..
iv) In what ways did the counselling help you?
Clarified your doubts / Helped you solve problems in the TMA / Got you started on studying the
course / any other …………………………………………………………….……………………
……………………………………………………………………………………………………..
v) What more did you expect from counselling?
……………………………………………………………………………………………………..
……………………………………………………………………………………………………..
……………………………………………………………………………………………………..
vi) Would you like
a) to attend radio counselling for the course?
Yes / No
b) to attend teleconferencing for the course?
Yes / No
c) your difficulties to be solved through letters from counsellors?
Yes / No
d) to use the INTERNET facilities for counselling?
Yes / No
vii) How much time did you take for completing the
Section I, …………………………
Section II, ………………………..
Section III, …..…………………...
Section IV, …..…………………...
of the assignment?
viii) Your overall comments on the Units 7, 14 and 15 and the course. (Write the comments on the
course after studying it.)
12
Section III
(90 marks)
Note: You must attempt Question 1. For writing answers to this Section, follow the instructions
given on Page 2.
1. i)
List the key concepts of Unit 7.
(1)
ii) What is the nature of the fringe pattern observed in Michelson interferometer if a) mirrors are
perpendicular to each other and b) if white light source is used?
(2)
iii) Explain the role of reflection and transmission of light in the production of interference fringes in
Febry-Perot interferometer.
(2)
iv) In a Michelson interferometer experiment, 100 fringes cross the field of view when the movable

mirror is moved by certain distance. If the wavelength of light used in 6000 A , calculate the
distance through which the movable mirror has been moved?
(4)
v) List two advantages of Febry-Perot interferometer over Michelson interferometer.
2. i)
(1)
Show that the electric and magnetic field vectors associated with electromagnetic wave oscillate
in-phase.
(5)
ii) Show that, for constant frequency, the amount of energy carried by an electromagnetic wave is
proportional to the square of amplitude of associated electric or magnetic field vectors.
(5)
3. i)
State and explain Fermat’s principle.
(5)
ii) A beam of light is incident normally on a slab of glass (refractive index 1.5). Calculate its
reflection and transmission coefficients.
4. i)
(5)
List the processes involved in the formation of image on the retina. Explain any two of these
processes.
(5)
ii) What are the functions of rods and cones in human eye? Do we need different types of receptors
to perceive different colours? Discuss in the light of Young’s theory of colour vision.
(5)
5. i)
What is an ideal polariser? If the transmission axes of a polariser and an analyser are at 45 from
each other, calculate the intensity of transmitted light with respect to the incident light.
(5)
ii) For a birefringent crystal, what is the relation between its thickness and the path difference
between e- and o- rays? For a birefringent material, ne = 1.553 and no = 1.546 for light of
wavelength 5.810–7m. How thick crystal will be required to make a half-wave plate of this
material?
(5)
6. i)
Interference fringes are produced by two superposing waves of same frequency and constant
phase difference. If their intensities are in the ratio 64:1, calculate the ratio of the maximum to
minimum intensity in the fringe pattern.
(5)
ii) Due to the superposition of two light waves, interference fringes are produced. Obtain the
condition for which intensity of the dark fringe will be zero. If white light is used for illuminating
the slits in Young’s experiment, the central fringe is white. Why?
(5)
13
7. i)
In Newton’s ring experiment, a liquid of refractive index 1.33 is placed between the lens and the
plate. In this condition, the diameter of 12th ring is observed to be 0.7 cm. If wavelength of light

is 5000 A , calculate the radius of curvature of the lens.
(5)
ii) A wedge shaped film is obtained by placing a thin wire between two plane glass plates at one end
keeping them in contact with each other at the other end. When the film is illuminated by light of

wavelength 5000 A , 50 fringes are observed. Calculate diameter of the wire.
(5)
8. State with reason whether following statements are True or False:
i)
For waves generated in a continuous elastic medium, two particles are said to be in opposite
phase if they are separated by a distance equal to one wavelength.
ii) Appearance of dark fringes in the interference pattern suggests that the principle of conservation
of energy is not obeyed in this phenomenon.
iii) In Fresnel’s biprism experiment, two real coherent sources of light are used.
iv) The principle of optical reversibility holds only when there is absorption of light in the medium
through which it travels.
v) Interference pattern in thin films is observed due to superposition of light rays reflected from the
top surface of the film.
vi) Interference in thin films is caused due to two real, coherent sources.
vii) The pattern of dark and bright fringes obtained in Newton’s ring experiment consists of
concentric circles.
viii)Michelson interferometer is classified as amplitude division interferometer.
ix) In Michelson interferometer, the beam splitter and compensator plates are identical to each other
in all respect.
x) Interference fringes produced by Fabry-Perot interferometer are much sharper than those
produced by Michelson interferometer.
(2×10)
Section IV
(80 marks)
Note: You must attempt Questions 1 and 2. For writing answers to this Section, follow the
instructions given on Page 2.
1. i)
List the key concepts of Unit 14.
(1)
ii) In producing a hologram, which physical parameters of the light wave are recorded. How
recording a hologram is different from ordinary photography?
(3)
iii) What is the role of reference wave in holography?
(1)
iv) Why is it necessary to use laser light for recording a hologram? Why do we require photographic
film of high resolvance for recording a hologram?
(3)
v) It is possible to record several holograms on the same holographic plate. Explain.
2. i)
List the key concepts of Unit 15.
(2)
(1)
ii) What is an optical waveguide? Why is it needed for optical communication?
(2)
iii) The refractive indices of core and cladding materials of an optical fibre is 1.58 and 1.38
respectively. Calculate the numerical aperture of the fibre.
(3)
iv) What causes the pulse dispersion in optical fibres?
(2)
v) Why does the energy of light dissipates while it passes through an optical fibre?
(2)
14
3. i)
Using Fresnel construction, explain the concept of half-period elements.
(5)
ii) The fifth boundary of a zone plate has diameter of 4 mm. If the wavelength of light used is

5890 A , calculate the location of principal focal point of the zone plate.
4. i)
(5)
What causes disappearance of certain fringes in the double slit Fraunhofer diffraction pattern?
How does slit width and separation between slits determine the order of missing fringes?
(5)
ii) In the Fraunhofer diffraction pattern due to a single slit, the slit is illuminated by light of

wavelength 5890 A and the screen is placed at a distance of 90 cm from the slit. If the slit width
is 0.15 mm, calculate the separation between central maximum and the first secondary minimum
in the diffraction pattern.
(5)
5. i)
A beam of monochromatic light is incident normally on a plane grating having 4800 lines per cm
and a second order spectral line is observed to be deviated through 30º. What is the wavelength
of the spectral line?
(5)

ii) Light of wavelength 5000 A is incident normally on a plane transmission grating. Find the
difference in the angle of deviation in the second and third order spectra. The number of lines per
inch on the grating surface is 5000.
(5)
6. i)


Sodium light of wavelengths 5890 A and 5896 A is incident normally upon a plane transmission
grating having 8000 lines per inch. Calculate the angular separation of sodium lines in the first
order spectrum as observed in a telescope with objective and eye-piece having focal lengths 15
cm and 3 cm respectively.
(5)
ii) What do you understand by resolving power of an optical instrument? Distinguish between
resolving power and magnifying power of microscope.
(5)
7. State with reason whether the following statements are True or False:
i)
ii)
iii)
iv)
v)
8. i)
For observing interference pattern, the two superposing coherent light waves have same
amplitude.
Light emitted by ordinary source is monochromatic.
The visibility of Young’s interference fringes produced by illuminating the slits by an extended
source of light is poor compared to the those produced by illuminating the slits by a point source.
It is much more easier to observe interference fringes using lasers compared to ordinary coherent
sources of light.
There is no spread in the frequency of a spectral line.
(25)
What do you understand by population inversion? Compare and contrast three level and four
level pumping schemes.
(5)
ii) Difference in energy of lasing levels of a laser is 12.2eV. Calculate the wavelength of the laser
light.
(5)
15