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Reg. No. :
Nu-":,..-L....Second Year
- M
^tch 2012
Code No. 1015Fot Stheme-I Candidates
Time : 2 HoursCool-o{f time : 15 Minutes
Part IIIPHYSICS
Maximum : 60 Scorcs
General Instntclions to Canrlidates :. There is a 'cool-offtime'
of 15 minutes in addition to the writing time of2 hrs.. You arc not
allowed to write your answe$ nor to discuss anything with others
dudng
the 'cool-off time' .. Use the 'cool-off time' to get familiar
with questions and to plan your answers.. Read queslions caxefully
belore answering.. All questions arc compul$ory and only intemal
choice is allowed.. When you select a questiorL all the
sub-questions must be answered fiom the same
questioh itself.. Calculations, figues and graphs should tle
shown in the answer sheet itselfo Malayalam version ofthe questions
is also provided.o Oive equatioru wherever necessiuy.. Electronic
devices except non-prograrnmable calculators are not allowed in
the
Examination Hall.
rn'klcg
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l. (a) Name the physical quantitywhich has its unit
joule.coulomb l. Is it a vector or ascalar ? (l)(b) Tuo plane
sheets of chargedensities
- o and - o are keprtn ar as shown in figure. Whalare the
electdc field intensitiesat points A and B ? (l)
(a) The resistance ,R' of aconductor depends on itslength ,/',
area ofcross_section'A' and the resistivity of thmalerial .p'. The
corectexpression conaecting R, /. Aand 'p,is
(q R=* to) R=pA/ (1)(b) The voltage-crment graphs for
two resistors of the samematerial and same radii withlengths Lt
and L2 are shown inthe figure. If Lt > L2, state
el,ra, eltbdffif qol6rD1do9o,
"o'lrulood e,rcenEsf,Qra)Jos aql6@"Jd{!!l po;6r(0] ooqooc,
miqeetaoc ? (l)+ o.
- o 4tcdsd oaod(rulolColgg o6n5 nuar..roer6doirA
"Jlt(d)(drol(d @,c6ml.m.o)-cnjcoer ia,q1@,o,l9Jlo.l6ot(IDl.oO,
6DI norrDl enncnliogfi_e,Jgg qerlq'ld o.ol.druioood)caot@ldoto ?
(t)
noJ atcer@,oloiloal ooc(Do(R), rooorfoq rnrg"
i4,5,*ff;3,,,H*?ffi,$J;( p) o0firrloj@)o?col ml(n-or_ogsiloldoJmt.
R, /, A. ono.rrt.ll (or@'letgg @ol(a)ca)6r)larr(jjo @c6rrt@oJ(rD
m)o_otc6,.\o
tu) R=#(D) R = pA,r (t)
L (a)
o)
+o.B
(A) R=+ re) R={
2. (a,-o
(4 "=+
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3. 3.The orderly distribution ofelechomagnetic
rudiationsaccording to their wavelength orliequency is called
electromagneticspectum- Identify the constituentmdiation of
ele4tromagneticspectrum which(i) is used for studying crystal
structure.
(ii) is absorbed by the ozone layerin the atnosphere.
(iii) produces greenhouse effect.L(v) used in medicine to
destroycancer cells. (2)
Using the data given below, state asto which of the given
lerlses willyou prefer to use as
(i) an eye-piece and(ii) an objective to construct,an
astronomical telescope ? Givercason for youl answer.
ooojBjlo) @,c(ro'ld, @,'lo6rD6dBo8ctaomolos (d,.oo(,
oo6d"$(oloibaeGDofl6;1(.8 croorA(dlctaoJog
5. orcog .o(mloloJm 1^rmiocorn-
GDslfiunc(f)oro'iloi t@,o16o14-oilocno)csrd mio"rCq"
noeT)][email protected](d. rOCOg .O.rrikololrrDol(Itj(o)lord,glocco'l
5r,loi(Dods6jlo6rn6gBoa
"oorcoemrnl ooerre-oro)6.(i) lelrpon "ers(r)
oro'ldolff)ojl-(r}ldceoc(,t@o}(m(d. *(ii)
noo@1@,giolotloer o?c'nrc6nd f f {olcgil GDolo6rrro oorq;cmoi.
re5(iii) "oo1o r.lrj"o tolrecotogerecaoymroi. (r V {oq,(iv)
6)6)r)113.\ ,rta,tor"ar.d,t
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(c) Alkali metals are most suitablefor photoelechic
emission.
(d) Davisson-Germer experimentproved the particle natur
ofelectrons.
(a) In the following nuclearfission rea.tion, N is thenumber of
neutons released.What is the value ofN ?
]rju + j' -+ lras, +
rr|ox"
+N(b) Complete the following
nuclear reaction equation.
le" + ln" -----+ j" + -- $(c) Two nuclei have mass
mrmbers in the mtio 1 : g.What is the ratio of theirnuclear
radii ? (l)
(a) Identify the logic gate.(b) Draw its logic s),rnbol.
(2)
6.
(c) ooncGsc @ettqld t"Jrec.ll_oror'lqi
"0gr4o 6o
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lcy'lf this logic gate is connected\'/ to a NOT gate, what will
be
the output, when
(i) A= I, B: 1 and(iD A=0,8=l?
8. Materials are classified intoferomagnetic, paramagnetic
anddiamagneric according to theirmagretic properties.
,-ktl Which one of the following is
u.b)
not ferromagnetic ?(A) Cobalt@) kon(C) Nickel(D) Bismuth
O)Define the term magneticsusceptibility. What is itsvalue for a
perfeci diamagnet ? (1)
(c) State the rcason why soll ironis used in
makingelectromagnets. (f)
9. The phenomenon in which elecriccurrent is gerc@ted by
varyingmagnetic field is calledelectromagnetic induction.
(a) Wlich law helps to detect thedirection of induced cunent
?Slate the law. (1)
(b) Explain what are eddycurrents, O)
(c) Write any two uses of eddycrurcllts. (l)
1015
(r)
(c) pa' cercsld; c('gloc(o).l oolNOT c(,)d olsl*l4c(fl,(i)
A=l,B:1(iD A-0,B:1orgcorccd er4'$oj152o,
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. Match theB c(i) Doppler ScatteriIrg Theory of
lieht(ii) Maxwell Red shift Coherentsoutces(iii) Ravleieh
Polarization AstiFnatism
Diflraction Speed ofGalaxies
Electro-magnelic
Blue colourof sky
(3)
,4nJ. 10. cdd
11. Given below i6 the graph betweenfrequency (u) of the
incident lightand maximum kinetic energy (Ek)of enitted
photoelectons.
-4(a) Define the
function andfrequency.
(b) Find the values of(i) threshold lrequency and(ii) work
function from thegaph. o)12. Nels Bohr explained hydrogen
spectrum based on quantirm ideas.-@ Draw the energy level
diagram
1 l. dr(o(r) Lol@,c@@ib(d GOoJ_iool(o)Jo (u) CdqDda.l@oCs).rDcn
.)cic gpad,olscem;a,g;o sa,ldoo ('(o)lcelds.lllo (Er)(d)eolel)gg
6nc.d rocoe rormrf
E
6
!zt0l-:
oldol0rrJ.
ofhydrogen atom.Name the differentlines obsewed inspectrum.
tems-workthreshold
0)sedes ofhydrogen
(r)
(2)
B
(a) rrrd@d' onoqt sloA, o(oc.&c_oiojj tonl@roafiul
ooqrrlol(Itd.!.jtdo}6,.
e.)(b) CtncooitoE cn
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l3;PD/(\oose rhe conecl relationoetween the transistorparameten
ct and p.
(A) p=+@) p=*(c) p=+@) p=#; o)Define the quantities d and p.
(l)Give their possible range ofvalues. (l)
-.(") Sho* the tansitions betweenenergy levels producing
thedifferent series. O)
(c) ryJorJa$id' rn,1o1rru)@,vd@6,6co6lDocco, no(r)rdgl '
oetc!_etlo,uAdolsaoioe, (soqdfiu.l.$c-(rr)@,od or(oei d,c6rrr1@oJe.
O)
IJ. (a) q. p Lscoi(rutqlp alo]olgol-6ud @@lelJgg
crucicr,o@olaoc(a,l 6c6n @oJcr, filq-Qjc6Jo O.ooo6otosJdo)@,.{A) o
= 1-q
ct
(B) p_*rO R =1lgto) p=Ifu (r)
(b) c, F "gXrrnc! d6q.jdot6. (1)(c) oP(!lqr,))os
ole{6!Boad6;
o)(c)
14. Spectrum allocations forcommunication are arrived at by
anDrernahonal agreement.(a) Narne $e agency which
administers the present svstemof frequency allocations. (l)
@) Draw block diagrams of anamplitude modulated(i) trursmitter
and(ii) receiver e)
Fill in the blanks :If'ol' is the angular frequencyoI a.c., then
the reactarlceoffered by inductance .L. andcapacitance .C'
are
ou3DJo3(oJ Gooaj (r)oE@,Jo,. (l )
oicdoto)c ojlctoa) GEoJ@[email protected])JgE .mjodtqo,
.oa.DJeJrrdol.rD@jcDrro(doqoDlaQJ qr3odlD !ol6g@AC6nj(a)
".EoJ "OsqEqrjla,c6rfi @rmooloCdol@,Jdqul on.oo6r, Co
tL@,,}a)oo@,@JcoJo o.rg)lm(oi ? (l)
O) oOoXJtggdcoraDlaerpadtrl 1sc@mlolgrnooficorl(rr )
daulr)lolooiaolo a6Hcdd
eDcoLo6sBs, orcqrdol@,. (2)
r4.
:2 15. fa)respectiveltXL=.--and
ojlscoo or,lotddol@, :'o)' (soo(,)etd Lonld,JaAqDl_
co,lgg noJ oo.aul. (rud6,rr-S]cd eqcdrudgoad L n",@,dcoulg(6al
C-cor;o [email protected] .tqooqotmt o)ncl6,oo^r-=- \=_ (r)l0l5
&= (r)
P,T.o.
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ft) Aa electric bulb ,8, and aparallel plate capacitor .C.
areconnecled in series as shownn tgwe. The bulb glows withsome
brightness. How will thegtow of the bulb affected onrjltroducing a
dielectric slabbetweh tbe plates of thecapacttor ? Give reasons
insupport ofyour answer.
(b) @erd'Lsld 6rusd6ni B_e)o.6:c,oend odQ, @,gcrnd;L-qrJo
.jto)im)h o,c#l-?qtcnrcoel 5rol do.mj.'ru'ud,Jlslr@
oetslnrld)ol_doJcml. 6ru!66Di ,^
^i ^r-- .,(rDdor$Sitdwed\,r/d. 6r!q,6ru
CaJ&CLrO,l,J)-ooc5rEloldolqDl. e4Jcol';aegcmt?d:,!glY:9d 'eol-
ooflL-r@erd;(sld;
^r,mifori"J6DJrrd6Dioq t"jan o orf-f L.u_rooaor o{)6gB5)(D 6n
cqjildo)o ?gotooo [email protected])6,.
(t)
Q)
-6 orr".-below are two "r""r"
(t)circuits A andratio of powercircuit B to that ofA ?
In the potenti ometer circuitthe balarce poihl is at X.
B. What is thefactor of the
shown, 16. frTli$#;"#^s"'#*ffiHe^
t6D6lqDl.
s'
#i3J"$"#''Ts-ffiff;i(a) oogcoDle4o ocealetco(6'_
o{niXprflTo n. oraarrf6qc,rd. '1f .y
(c) d B ooqr,1 o5rd perLe,ld,(ruooJlsJ6q6 @rcoc
o6,;sr_:t6to1doJ0D,l. a-o]o.oo,pA_@-los@lo
^lold ^!c&o)6,u1rdr@'rerlgg lEbo,lorc(',o
ro;LoForcao,loldo)o ?xL= 3R
X, =3R
l0l5
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(c) Cell P is replaced by anothercell whose e.m.f. is lower
than
t ofcell Q. o)Yo-}l are asked to compare thee.m.f s of two cells
using apotentiometer. Draw thecircuit diagnm for this andexplain
how you willdete.mine th6 ratio ofe.m.fs. (2)
17. Oe6tead found that moving chargesor curents produce a
magnetic fieldin the srmounding space.
(a) An electric current is flowingdue south along a power
line.What is the direction ofmagretic field (i) above jt and(ii)
below it ? (1)
O) DIaw a neat and labelleddiagram of a cyclotron. Statethe
underlying principle of itsworking. e)
L{6} A cyclohon's oscillatorfrequency is 10 MHz. Whatshould be
the operatirgmagnetic field for acceleratingprotons ? e = 1.6 x
10-19 C,mass of proton r\ = 1.67 xto-2?tg. e)
l01s g
(b) R aud@mdol S ollaa&jl4coe O)(c) oouc6 p-dd d@,oq
e-oile{od,Jo6rmD p.o6)o.ooo-d. gggosDd aejslileJcd. O)(d)
oolcgoaad4cokd
eoro(oc_utd @drBl o(n)gJl@,glosg9o.o61o.o4od o_,co.ooJoo.JElocd
rrl6lBogcd Grooj_00j6,,*FiloldolcDl. A(o,kDc(q)lgEau6@,J:5
ctr)(oL('o oocJoo;o.sDoJo.lc@o d{D6sBo(r' 66rBJ_"jldldoloocd
ailuD6oc@6,J@,. (2)
"Jejl@olfir, 4lcdsl@,oA GEoS6,1(oEoooroJJ.o {.ojotcooo
dlgler}o6cooila, o6rnDeto cruS.Eloel;oocnlncdqllad eo6rBoot.(a) aol
orera ooerr1tel,os
ot6rdd' rt@qf d oool6JJ@,Lojrrlort@oJm). lqrd.o.lcDl(i)
oJ6Citerlo liit ,orcovo,So6coat@, o6ntDet(ootooe B10ooao.rcotoloolo
? O)(b) ooouqscotsc5rr,loo3 ec(/)-6rBUd
GDsaocgodslcolo,la)lgg4flt.6ro olod@ol@' cD(o.rocre(oJCr6orDCf,
o)orJo oiooR_oc@o]6. Q)oofiuc*co(sc6ntocra acaD}'oeigd Ldol@,rdcu,l
l0 oo(,coooddad cD6lfiD). atoJcosc_6ml66)9 cpdmercogJo.Jgcd
@rgox/oJo9@ ecoo.teooru(('}G ool(oaocadloldolo ?e = 1.6 x 10-19 C,
cLdJec5c6naqc(rf\= 1.67 x 10-27 kg. (2)
O) Resistance S iskeeping R constani.
increased,
.(l)
I
\l'7.
(c)
P.T.O.
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18. A spherical surface of radius ofcurvature R, sepamtes a
rarel and adenser rnedium as shown in thcfigure.
(a) Complete the path of theincident ray of light, showingthe
formation ofa rcal image. (1)(b) Derive the relation
connectingobject distance 'u', imagedistance 'v', radius ofcurvatue
R and the reftactiveindices n, and n2 of the twomedia. e)(c) A thin
convex leas of focallength 5 cm is used as a simplemicroscope by a
person withnormal near poiDt (25 cm).What is the magnifying
power
Iofthe microscope ? (1;)
ORIn the figure PQ is a rayincident on a pism ABC.
(d) Complete the ray diagramshowing the passage of light.Mark
angle of ircidence i,angle of emergence e, mgle ofdeviation 6 and
angle ofrefractions rl and t2. O)
18. R coortcoo$ acod 66colqolgg5lo) G(ocgo)elq
(rDcL(Brodlsl(qJorlo 6,lo6wrorloc(o @c(r).\o-5sBog .jl(@(o('il(S
@,c6rTrlcDo)J-cdcoe! c(ll6o)loli0ol@o)m).
(a) ool cncord pco' olo.looecgpc(nlgg txr
ar)aoL(,)od1doro,1@co16. 0 )
O) 'u', 'v', & n,, n" goooreruoi
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(e) Using the diagram obrainrelation
6=i+e-A(f) The critical angle for diamond
is 30". What is its reftactiveindex ?
19. The idea of,Electric field lines, isuseful in pictodally
rnapping theelectric field around charges.
(a) Give any two properties ofelectdc lines offorre. O)
O) State Gauss's theorem inelecAostatics, O)(c) Using the
theorem, dedve a!expression for electric fielddue to a uniformly
chatged
, . $lslberical shell\',-Vfl(r) at a poinr outside lheI
shell(ii) at a point inside theshell.
(e) 6=i+e-A ao.rD cruoryc@(o"ll(oioufl o(d mr.o"coroororcj.
the
rls (h
(d) ^
A point charge of+ lO Fc is atd'a distance of 5 cm directly,,
above the cenhe ofa square of
side l0 cm as sho&r in 1igure.What is the electric flux
(D rur(oro6ltskae (p,Ebod c@'16a630" 6D@,JqDJ.
.tto.cd,g.lojgacAou*nd
"0(crorcaotol@op ? O+)
,rc6ssJ@,03dd .4glolgg ooqBJJo)
@5mDejo 4nLor16,o:ldocoA, oootBJJo.,6nJeJcoor@,04' doqD
cD('oao)o9nJ@lcOodsJ(mJ.(a) oocuoJyor 6ruet c.o6u6glos
o6oro@,1e{o o5rd @)5rD66BuaooeJ.0,l6. 0 )O)
geidctscqlpgl&nirer o@c\.njcnlcoroogotmiotcorloo;o. (11(c)
g\rrr$or}o fiilaor@o gojceJo(]lt.jco}6rDlcoogoc{ol
"jcrdsdodgods q$oon.,[email protected] (i ) arloorolo(ll)
raD@,(droJo 6njl.Bl@oglet)_erecoJrm pera,,"Lsld no1
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Besides its use in storing chaxge, acapacitor is a key element
of mosta.c. circuits.(e) What are the factors on which
the capacitance of a parallelplate air capacitor depends ?
(1)(f) Define the term 'dielectricconstant'ofamedium. (1)
(g) Tlvo capacitors Ct and C2 areconnected in series. Derive
anexpression for the capacitanceof the combination.
(h) Find thecapacitance ofgiven in the network.
dc{acgd auoeol4oolaoidoJff orl-o(T)s$o oro.rD e'H9(Iulgii 40.
rru].(ru(d@,ll5l@,0llos @ol m)]Lolocq,nelsalo 6,)sl@c6nJ.(e)
oo;
"jcoeri adg' "O(o)dodc(rulgdooe edo(r\,lAadmjn0oo,Jod6r
OXru'or;orOOgcr9(@@14ilo1@FDl ? O)(0'oo(tl)e&{dld
eer6r6qBoe"of)oo,cocTDfiri q'd"eldtgilaidl@Fnl. p.9a\.,-o(a,trd,oE
oq &rgc(ntgorrul(T))gg m)o.ulelo e6r6rB_
d)ds
(+)
(dnrt6,.equivalentcapacitors
4pF
-l--Ao---J II IFj--i- l2G9ur)
(h) ocoe .dr(IrnololcD (oJooJ-erco,los 6dcaul0d(n;
66rBl-dils'ldo)@,. Clt3pF
1015 t2