Deemed University 2009 A.M.I.E.T.E Electronics
Tuesday, 30 April 2013 04:35Web
Page 2 of 2
h. Electromigration in an IC chip refers to
(A) Grain boundary diffusion of Al in Al interconnections.
(B) Grain boundary diffusion of Cu in Al interconnections.
(C) Diffusion of Si in Al interconnections.
(D) Diffusion of oxygen in Si.
i. The units of are
(A) C-m2. (B) Hm–1.
(C) Fm–1. (D) Dimensionless.
j. The degree of freedom when ice, water and water vapour co-exists in equilibrium are
(A) one (B) Triple point
(C) –1 (D) 0
ans any 5 ques. out of 8 ques..
every ques. carries 16 marks.
Q.2 a. elaborate deficiencies of Rutherfords nuclear model? How these deficiencies were overcome by Bohrs atomic model? (8)
b. obtain atomic packing factor for FCC. Also compute number of atoms per mm2 surface area in a plane for copper which has FCC structure and a lattice constant a = 3.6110–7cm (8)
Q.3 a. discuss with simple sketches the arrangement of atom around an edge dislocation and a screw dislocation. Also illustrate Burgers vector on the sketches. (8)
b. State and discuss the utility of Gibbs phase rule? (8)
Q.4 a. State Ficks 1st and 2nd legal regulations of diffusion. How diffusion coefficient is influenced by temperature? (8)
b. A copper wire of area = 510–6 sq-m carries a steady current of 50A. Assuming 1 free electron per atom compute
(i) density of free electrons
(ii) avg. drift velocity of electrons and
(iii) relaxation time of electrons
[for Cu = 5.85107 mho/m and =8.9103 kg/m3]
Permittivity of free space = . (8)
Q.5 a. What is Hall effect? elaborate the applications of Hall effect? How the concentration of charge carriers (electrons or holes) in a semiconductor can be obtained from measurement of Hall coefficient? (8)
b. If the carrier concentration for silicon is at 300K, determine its conductivity and resistivity. Also compute drift velocity of holes and electrons if the applied electric field is 50 V/cm. provided that , for silicon and the electronic charge, coulomb. (8)
Q.6 a. discuss Dielectric strength of a dielectric material. On what factors dielectric strength of a dielectric depends? (8)
b. What is Ferroelectric material? Write a brief note on any 2 ferroelectric materials? (8)
Q.7 a. discuss the subsequent magnetic parameters:
(i) Magnetic moment.
(ii) Magnetization.
(iii) Magnetic susceptibility. (8)
b. Name the magnetic material desirable for the core of the transformer listed below? Also discuss why?
(i) 60 Hz power transformer
(ii) AF power transformer
(iii) RF power transformer
(iv) Pulse transformer (8)
Q.8 a. What do you understand by ION implantation? provide at lowest 2 applications where the process of ion implantation is used. (8)
b. Distinguish ranging from cold and hot forging. Write their advantages and disadvantages. (8)
Q.9 Write short notes on any TWO:-
(i) Soldering and Brazing.
(ii) Photolithography.
(iii) Hardening and tempering. (8 2=16)
| Earning: Approval pending. |
