University of Mumbai 2004 B.E APPLIED SCIENCES-I - Question Paper

(APPLIED SCIENCES-l) (JUNE. 2004)
N.B.:
(1) Question No. l is compulsory.
(2) Answer any 4 out of remaining 6 ques..
(3) Assumptions made should be clearly said.
(4) Assume any suitable data wherever needed but justify the identical.
(5) Figures to the right indicate marks.
(6) Illustrate answers with sketches wherever needed.
(7) Answers to ques. should be grouped and written together, i.e. all answers to sub-questions of individual ques. like ques. Nos. 1,2,3 etc. should be answered 1 beneath the other.
(8) Use legible handwriting. Use a blue/black ink pen to write answers Use of pencil should be done only to draw diagrams and graphs.

part I

1.(a) Show with the help of suitable sketch the proper positions and the co-ordinates of atoms in a unit cell of diamond structure. provide position co-ordinates of atoms within the body. Consider 1 atom to be the nearest to the origin. (5)

(b) discuss procedure to determine Miller Indices of a crystal plane which intercepts all the 3 axes. (5)
2. (a) describe - (i) ligancy and (ii) critical radius ratio. obtain critical radius ratio for ligancy '8' (eight). (5)
(b) obtain packing density of-(i) BCC and (ii) diamond crystal structure. (5)

3. (a) discuss with proper sketches - (i) direct and (ii) inverse piezoelectric effect. discuss its application in production of ultrasonic waves. (5)
(b) 2 ships are anchored at certain distance ranging from them. An ultrasonic signal of 50 kHz is sent from 1 ship to a different by 2 routes - (i) through water and (ii) through atmosphere. The difference ranging from time intervals for receiving the signal at the other ship is two seconds. If velocities of sound in atmosphere and in sea water are 348 m/s and 1392 m/s respectively, obtain the distance ranging from the ships. Also obtain time taken by the signal to travel through water. (5)

4. (a) An electron having charge 'e' mass 'm' and velocity V is entering normally a limited uniform magnetic field of length '/' and strength 'B'. obtain expression for deflection of electron path on the screen
placed at a distance 'D' from the center of the magnetic field. (5)
(b) compute velocities of - (i) a proton and (ii) an electron accelerated through a potential difference of five kV. (5)
(Given: electron mass =9.1x10 -31kg.
proton mass = 1.67 x 10 27 kg.
charge on electron =e= 1.6x 10-19 C.
charge on proton =e= 1.6x 10-19 C).

5. (a) discuss formation of energy bands in solids. discuss classification of solids into conductors, insulators and semiconductors on the basic of energy band theory. (5)
(b) discuss with neat sketches formation of P-N junction. discuss potential barrier and its behavior in forward bias and reverse bias conditions. (5)

6. (a) discuss construction of Cathode Ray Oscilloscope. discuss simple time base circuit. (5)
(b) Show that the De Broglie wave length of a charge particle is inversely proportional to the square root of accelerating potential. (5)

7. Write notes on :
(i) Electrostatic focusing (5)

(ii) i/p characteristics of transistor in CB configuration. (5)

part II
N.B.
(1) Attempt 2 parts on various answer-books.
(2) Assume suitable data if necessary.
(3) In part II ques. No.l is compulsory. Attempt any 3 ques. from ques. Nos. two to 7.
Atomic Weights : H = 1, C = 12, O = 16, Ca = 40, Mg = 24, Na = 23, S = 32, CI = 35.5, is = 28.

1. (a) elaborate advantages of Hot lime-soda process? (20)
(b) What are sources of air-pollution ?
(c) Which kind of lubricants are needed for cutting tools, turbines etc ?
(d) Explain phosphate conditioning as a internal treatment method in case of boilers.
(e) Differentiate ranging from Addition polymerization and Condensation polymerization.
(f) 9 ml oil is taken from machine and it requires 1.5 ml of 0.04 N KOH. obtain acid value, (density of oil = 0.81 g/ml.).
(g) What are sources and effects of CO as an air-pollutant?

2. (a) Explain: Boiler corrosion; (5)
(b) Write a note on Viscosity and Viscosity index. (5)

3. (a) define transfer moulding in polymers. (6)
(b) compute the amount of time and soda needed for 50,000 lit. of water sample containing - (4)
CaCO3 = 10 ppm, Mg(HCO3)2 =14.6 ppm
CO2 = 4.4 ppm, CaCl2= 22.2 ppm
MgCl2 =9.5 ppm, SiO2 = 2.8 ppm

4. (a) elaborate the moulding constituents of plastic? (6)
(b) Explain: Ion-Exchange resins. (4)
5. (a) What is sewage ? How is it treated by Activated Sludge Method ? (7)
(b) elaborate functions of lubricant? (3)
6. (a) discuss : Crepe and smoke rubber. (4)
(b) An exhausted zeolite softener was regenerated by passing 75 liters of NaCl solution having strength 75 g/lit. If hardness of water is 300 ppm, then claculate the total quantity of water that is softened by zeolite softener. (6)
7. (a) What is caustic embrittlement in boilers ? (5)
(b) What is cloud point and pour point ? How is it determined ? (5)

Earning:   Approval pending.