University of Mumbai 2006 B.Sc General Applied Science II - Question Paper

MUMBAI UNIVERSITY

one year 2sem

Applied Science II

May 2006 (Revised Course)



part I

N.B. (1) ques. No. one is compulsory. Attempt any 2 ques. from ques. Nos. two to 5.

(2) Attempt both the parts in separate ans books.

(3) presume suitable data and symbols if needed.

(4) Figures to the right indicate full marks.

1. ans any 4 ques. from subsequent 6 questions: — (20)

(a) discuss why in Newton's ring experiment the rings are unequally spaced? What will be
the effect on the diameter of any ring if air gap ranging from the lens and the plate is
changed by liquid?

(b) discuss the subsequent :

i. Why is the cladding rarer than core in fiber optic cable?
ii. What is the measure advantage of graded index fiber over step index fiber?
iii. When is the use of laser preferred than LED in fiber optic communication?
(c) Write the difference ranging from fission and fusion. What is stellar energy? Why it
can't be produced on the earth?

(d) How Bragg's legal regulations can be used for analysis of crystal structures?

(e) Compare ranging from ordinary source of light and a Laser. What is the Importance of
metastable state and pumping in the production of Laser?

(f) A parallel beam of light ( X = 5870 A0) is incident on a thin glass plate ( µ = 1.5),
such that the angle of refraction into the plate is 60°. compute smallest thickness
of the glass plate which will appear dark by reflection ?

2. (a) discuss the significance of Mosley's legal regulations. When an electron from the L-shell is transferred to
K-shell, X-rays emitted have a wavelength of 0.788 A°. What is the atomic number of this
atom? Screening constant b = 1, Rydbergs constant R = 1.097 x 107 /m. (8)

(b) What is diffraction grating ? What is grating element. A diffraction grating used at
Normal incidence provide a line (5400 A°) in a certain order superimposed on the violet line
(4050 A0) of the next order. If the angle of the diffraction is 30°, how many lines/cm are
there in the grating ? (7)

3. (a) discuss with neat figure the construction and working of a Ruby laser. (8)
(b) In an uncontrolled fission reaction one milligram of U235 fissions out in 1. microsecond.
compute the power of explosion. provided that the energy produced per U235 fission is 200
MeV. (7)

4. (a) discuss with figure the construction and working of G. M. counter used for counting nuclear
particles. (8)

(b) A soap film (µ = 1.33) on a wire loop held in air appears black at its thinnest portion when
viewed by reflected light. On the other hand a thin oil film (µ = 1.20) floating on water
(µ = 1.33) appears bright in its thinnest portion, when similarly viewed from the air above.
discuss these phenomena.(7)

5. (a) The spacing ranging from the principle planes in a crystal of NaCI is 2.82 A°.
It is obtained that 1st order Bragg's reflection occurs at 10°. (8)
(I) What is the wavelength of X ray ?
(II) At what angle the 2nd order reflection occurs ?
(Ill) What is the highest order of reflection seen ?
(c) Write the difference ranging from Holography and Photography ? discuss the process involved to
construct the hologram with proper figure. .(7)

part II

N.B. (1) ques. No. six is compulsory. Attempt any 2 ques. from ques. Nos.
7 to 9. (2) Atomic weights : C = 12, H = 1, S = 32, O = 16, CI = 35.5. N = 14.

6. Attempt any 5 from the subsequent :— .(20)

(a) What is cracking ? discuss the advantages of catalytic cracking over thermal cracking.

(b) discuss scope and importance of biotechnology in medicine and agriculture.

(c) . discuss how sulphur can be estimated in coal.

(d) Write a note on— Pitting Corrosion.

(e) discuss how you would control corrosion by improvement of design.

(f) A sample of coal has subsequent composition by mass C = 70%, O = 8%, H = 10%
N = 3%, S = 2%, Ash = 7%. compute H.C.V. and L.C.V. using Dulong formula.

(g) provide the composition, properties and uses of Duralumin.

7. (a) How do the subsequent factors influence the corrosion rate— .(8)

(i) Position of metal in glavanic series (iii) Temperature
(ii) Relative areas of anode and cathode (iv) pH of the medium.
(b) What is Petroleum ? How is crude petroleum refined ? Name different products
found from it ? .(7)

8. (a) i) elaborate plain carbon steels ? How are plain carbon steels classified on the
basis of their carbon content ? .(2)
(ii) Write composition, properties and uses of— (a) German Silver (b) Nichrome. .(6)

(c) discuss the manufacture of biogas from waste material. provide composition, properties
and uses of biogas. (7)

9. (a) Mention the different methods of metallic coating and discuss any 2 of them. .(8)

(b) (i) compute the weight of air needed for complete combustion of one gm of coal
containing— .(4)
C = 72% H = 10% 0 = 9% N = 3% and remaining being ash.
(ii) discuss knocking and role of antiknocking agents in gasoline. .(3)

Earning:   Approval pending.