Old Exam Papers June 2012 (Set 2)

feyj lwpdkad ds inksa esa fdlh fØLVy tkyd ds fy,
ryksa ds vUrjky dks le>kb;sA 4
2. (a) Explain meaning of coordination number and packing
fraction in crystal structure. Calculate these for face
centred cubic structure. 6
fØLVy lajpuk esa leUo;u la[;k ,oa ladqpu xq.kkad dk
rkRi;Z le>kb;sA ,d Qyd dsfUnzr ?kuh; lajpuk ds
fy, budh x.kuk dhft;sA 6
(b) A metallic crystal has lattice constant 2.9 Å. Find
the number of atoms present in its unit cell if atomic
weight of metal is 55.85 gm/mole and density is
7870 kg/m 3 . 4
fdlh /kkrq ds ?kuh; fØLVy dk tkyd fu;rkad 2.9 Å
gSA bldh ,dd dksf"Bdk esa fo|eku ijek.kqvksa dh
la[;k dh x.kuk dhft;s tcfd /kkrq dk ijek.kq Hkkj
55.85 xzke@eksy ,oa ?kuRo 7870 fdxzk-@eh- 3 gSA 4
3. (a) Prove that Madelung constant for NaCl crystal is
1.7476. 5
fl) dhft;s fd NaCl fØLVy dk eSMsyqax fu;rkad
1.7476 gksrk gSA 5
(b) Explain Schottky defects in a crystal. 5
200 2 PH-10
9. (a) Discuss Hall effect in semiconductors. 6
v/kZpkydksa esa gkWy izHkko dk foospu dhft;sA 6
(b) Explain photovoltaic effect. 4
izdk'k oksYVh; izHkko dks le>kb;sA 4
10. Write notes on any two of the following :
(i) Isotope effect and Meissner effect in super-
conductors
(ii) Hysteresis effect and Hysteresis loss
(iii) Photo-luminescence and its explanation
(iv) Langevin's classical theory of diamagnetism 5+5
fuEufyf[kr esa ls fdUgha nks ij fVIif.k;k¡ fyf[k;s %
(i) vfrpkydksa esa vkblksVksi izHkko ,oa ekbluj izHkko
(ii) 'kSfFkY;rk izHkko rFkk 'kSfFkY; gkfu
(iii) izdk'k&lUnhfIr vkSj mldk Li"Vhdj.k
(iv) izfrpqEcdRo dk ySaxfou dk fpj&lEer fl)kUr 5+5
PH-10 5 200