Uttarakhand Board Class 12 Question Paper 2023 for Physics

Uttarakhand Board
Question Paper
CLASS 12

+di. gBa gEI d riwl = s
Roll No.
No. of printed pages : 8

L29 42e (rGUl
2o23.
rfuftnq(ffiol
PHYsIcs (Theory)
rrrrdl'3qoill tErrfo: ZO
Time:3Hoursl tMax.Marks:70
fttsr ' (i) {fl srr q7 d S-d 28 qq{ dt qtft ssq glFr{rd f;t
Directions : There are in all 28 questions in this question paper. All questions are compulsory.
(ii) rfrt tg Fr€rfRn 3i6 st'6 Hq-q siftna frt
Marks alloted to the questions are mentioned against them.
ttiil s-d-6 pq 6\ tarqd-6 frS dm sEFfr r.rq fiBst
Read each question carefullyand answerto the point.
(rv) xr{ risT t e6ffio
mra tt {s nq{ b r#6 qus b rr< ttar< fro,ffi ftt w tt
t
s& fr-drcq 3rqft rf,igkor iiftftsst sr< riwr z z ilo. FrFf,d raftq qs{ Ht
Question No. 1 is muitiple choice question. Four options are given in answer ofeach part of
this question. Write correct option in your answer book. Question No. 2 to 7 are definite
answertype questions.
(') qqq yqT 1 6'r rd6 qf,crs uin si6 6TSqr t tt
qsf, rr{
z z ffiF rir 3i6 b f;l
naiq risr a t t7 ffiD d 3i6 b qsq dt sqq dsT 18 t 25 il6 dI eio b qw
frt nrq dwl 26 t 28 cr6 qtr 3i6 b w.T f;t
EachpartofQuestionNo. l carriesonemark.QuestionNo.2toTareofonemarkeach.
Question No. 8 ta L7 are of two marks each. Question No. 18 to 25 are of three rnarks
each. Question No. 26 ta 28 are of four marks each.
(\1) {s sqq-q?{ d qqq q{ 6t$ ff,orq qfr t aPnfr 6frrq es{it 3rffi6 koro s-dm
fu-qT r-qT t-S qs{tiitr+a uo fro,ru 6T fr rn{ frfrst
ti
There is no overail choice in this questionpaper, however, an internal choice has been
provided in few questions.Attempt onlyone ofthe given choices in such questions"
(-1 f,d 3ilqsqcr s) srq frqfrfua tltfuo Frffdio} b qito'r sqqtr ffi rr6t d -
Wherever necessar,v, you may use the values of following physical constants -
c:3x I 08ms l, h:6.6* 10-34 Js, 11.6* 1 0-1e C, trto=4fixl tr7 TmA 1, =9 x 10s N m2 C-2
*
ffiq fr g6fr (mass of electron) m":9.1x10-3'kg, # o1Ti6fr (mass ofneutron)
m,:l .$l x lQaT kg, frffiflq fudi6 (Boltzmann's Constant) lr I .3 8 I x 0''z3 JK-r ;
1

3TfdllTdf dqf (Avogadro Number) No:s.QlxlQ23 mol l.

Ir I [P.r.o.

1. (6) 1fum.**q(GRd{Wqds-sf 6tftt- 1

(i) 1 qr (ii) 1{ffi{-dr6
(iii) I srf (iv) r du
Energy of an electron, accelerated at 1 vott potential difference is-
(i) 1 Joule (ii) 1 electron-volt
(iii) 1 erg (iv) 1 watr
(q) ern Frfr J HEr s{rdrd ilr vo it sqcr t - 1

Relation between current density I and drift velocity vo is -
(i) J=h€va (ii) J--:-
(iii) J=T (iv) J=0€vo2
(lT) ffi ro sqFI gryslq e}r fr s6 Seffi M b dwqa q}qT 6Tdl d r
fffiq 6r qp;
6tlr- 1

(i) qrtrrcndR (ii) *fgf,ioT{
(iii) grfloR (iv) H{m t#q
An electron enters perpendicularly in a uniform magnetic field. The path of
electron will be -
(i) Parabolic (ii) Eilipticat
(iii) Circular (iv) Straight line
(u) da o'r fr=qq Bv rX6- {rEr b ti<erur q< snenRa tl 1

(i) 3TraqT (ii) s.5f
(iii) gnsdr"T wkRT (iv) dtrr
Lenz's law is based on the conservation of which physical quantity?
(i) Charge (ii) Energy
(iii) Magnetic flux (iv) Momentum
(s) ffifuo itt 6t{ fr r<Tf f.g- g6blq art Se 1

(i) €dftilt{ (ii) tMmt
(iii) Erm Hrt (iv) {S ti res arfr

42e(tGU) 12\

Which of the following waves are electromagnetic waves?
(i) Sound waves (ii) Radio waves
(iii) Water waves (iv) Waves produced in a thread
(q) 6o061ur qr& frtr t s-srq frf,dq d fuifr { uo fu{q 300 6trr t ffid df; tr
fr'fl w fu{q 6-r a{Trr6Fr 6\"r t- 1

(i) 300 (ii) 450
(iii) 600 (iv) 900
A ray deviates by an angle 300 in a prism of angle 600 in minimum deviation
condition. The angle of incidence of ray on prism is -
(i) 300 (ii) 450
(iii) 600 (iv) 900
(u) cig-Sffi qrmg fr faqiq d serq'6eTr 6t fuqr o.s3A0 tt fs# ftfi 6&Tr fi
fuqi dnt- 1

(i) 4.77f (ii) 1.6eAo
(iii) 1.06A0 (iv) 1.0A0
In hydrogen atom, radius of first orbit for electron is 0.5340. Radius of it's
third orbit will be -
(i) 4.77N (ii) 1.6eAo
(iii) 1.0640 (iv) 1.0A'
(E) p-n HRr grds & srqeilq r{fr d dt fr- 1

(i) brn 6tcx (ii) bEaFWq
(iii) ffiEotc<#t (iv) r6)d,-{, TEfrq{q
In p-n junction diode, the depletion layer consist of -
(i) Only holes (ii) Only electrons
(iii) Electrons & holes both (iv) Neither holes nor electrons

42e (tGU) I3I lP.T.O.

2 B# qnqE t eHrEffi e*r 6r fi{ qH
J2 A*r *,*r mr mf qr€zr {f, qr;r Hrd dfor 1
arternarins current is
ln::?:;:J:;,:r Ji A in a circu*. Find roor mean square
3 fum rn-Aq d{rr d
Ttov Hft frl mi aoar Btrr fnt { $ftr;tr ftrfusr 1
jf#|1r;."', between focar rensth (F) and- radius of curvature (R) of a
ff:i
4 ftDrqr *gd qrr qr kDTsr bt
#rdr &.qr{rd d qr6 ar<r r<ffia ffirsr
show graphicary the effect of intensity l
of Light on photoerectric current.
qtriir 61g.frf aer frtrr
5
d swrr
write the reration between energy
fur 1
and momentum of a photon.
6 61 q-{fig fuT zd?rdqrr' ri-*, e tr gsg ilfir- d
ffi - agH of v*,, B.Ffi
Any erement has atomic number
z and mass number A. How many neutrons1
will be there in its nucleus.

7 'AND' ifc air qft1qq afur6
frfusf
Write Boolean expression for ,AND, 1
Gate
B' L2pF 6r 16 ri€nR7 sov &fi t 6sr dr H*,rF* d fud+
R,* d,d sfrf riftH *fti
to 50v batterv. How much ere*rosrati.
Xj3.T'Ir1':tiliffifected un"rgy i
s. drfiTfuo (ffi{ fr Bdf erq b a} oxq ftffir
Give two reasons of energy loss 2
in actual transfonmers.

10' qrE qrelfto F€r# d s-Fi flfr s.o
tfuzn fi rmT o.or torrs { vgu
trfu6 susfr d rcE iRfr frw Erfr6 sd 15,000 d sr# d dr
3Tdqfug*t_aroffiul dE dil
\"" tr v'u
\ ' uq gusffi b qqq
2
If the current becomes zero in 0.01
second in the primary coir carrying
current then the induced e'm'f. 3.0 A
in secondary coil is 15,000
volt. Find the coefficient
of mutual inductance between
these coils.

42e (rGU)
I4t

11. 30,000d rrtlTtsd d tqF gryfr1q il$r d 3rrgfr Firil dtsst qd ilfi dqq b fu.s qrr
61sdftfd arrft tl Z
Find the frequency of an electromagnetic wave of wavelength 30,000 d. Which
part of the spectrum is represented by this wave?
12. 6000d ilffisjC oT kFIsI dt-g t 1 .5 $q{dqi6 Erd qeqq ii rdyr 6krT t t qrrsq C fsor
trr oen sTgfr srd dBu I 2
Light of wavelength 6000d enters from air into a medium of refractive index
1.5. Find it's velocity and frequency in the medium.
13 . qfr orrq oiu or EIg b srter m-rfu6 o1u1 a1 140 * rir mrrq 6iu t si &fl b ftrn €trir{
.

fuwr 3ntiq [uf blftut 2
If the critical angle of crown glass with respect to air is 4L.L4o then complete
the adjacent ray diagram for a prism made of crown glass.

3[Ql?rrloR
ffi qlTaetr qTEzIq o.r qlqur olur irt eer Jfl qrszg iiprorq"r ol qro u tt qfr Frdfil d
milvr d urm c d dr i, o.r wq c erqr, b rii C rdffira dfrsr
Angle of polarization of a transparent medium is io and speed of light for that
medium is v. If speed of light in vacuum is c then represent ip in terms of c and v,
14. wmtr("gagtrmrqrqifrrdftxur3Trtqcqr$Ar z
Draw the labeled ray diagram of reflecting telescope.
ls. ilr 3d 3il93i b qruia ffi tffi q'dpf of ffi sfum qnr 3ro$q 16 onlrtr
2
What percentage of a radioactive substance will remain left after four life periods.

16. 'LED' ffiT t? LED b'6q qrfu qtrqfto drqftq fuifi
wFTr d ai mn+ Frfusr 2
.
What is 'LED'? Write two advantage of LED over conventional incandescent low
power larnps.

3reEII/oR

f{r sRfu d mrdlruntft irqsTr$st
Explain the working of Zener diode.

42s(rGU) Isl I P.T.O.

17. EffiqdrrftqqftTRr0dQnf,$affiHsu{rdfrfddBsr 2
Write Coulomb's law and show it in vector form.
18. 1.5 pc 3f{ z.s rrc sn}si dr& d qefl rf& 30 crn $ fuId dl *t'i3TrM o1Fmfi ar&
tur b q€q kd w kgd ela ar+ dfrEt g
Two tiny spheres carrying charges 1.5 pC and 2.5 pC are located 30 cm apaft.
Find the electric field at the midpoint of the line joining the two charEes.

le. fuffiqlft 6-r fu6Fd ffiqsl fdtlqqrfr E6 3TrRt ffifi fr are mrd ormr t, dils
Write the principle of potentiometer. Potentiometer works as an ideal voltmeteq
why?

zo. d#{ frEr;d b sirem r{ dt6 gs6FE d qrrsr drfret 3
Explain ferromagnetism on the basis of dornain theory.
21. +d ftd qt qRqq C 'B' r'o. saq 61 lrdffid 6rrTT tt qft drd d 3Trqfr o1 *.rar 6-{ frqr
Hr-q Ftrrc' irsrT 'L' b qfq fos q-6T{ qRHffid e}f BTtrA fu cm of aro ffi
61 3
In the circuit given below 'B' represents a bulb. If the frequency of source is
doubled then how should 'C' and 'L' be changed so that brightness of the bulb
remains same B

tC

22. tr6 Frf, ds b rcref mr 3iq-ilfu6 n tt gt n1 3rrsfrr6 aTd ftFS qT€qEi d gdr frqr snor
tt roni 6r tr6 srn-fi fu{rT T-a, d=s w anqfr-d E)-dr tg fr'q'qftfuiftrC d 3{rdffid
fr{uT b q'a 61fukd fiBs- g

The refractive index of a convex lens rnaterial is n, It is dipped in a medium of
refractive index nr" A parallel beam of light incidents on lens. Depict the path of
refracted ray in foilowing conditions :
(i) D, ) r (ii) n, . n (iii) tr, = ft
3IeIEII/OR

ud si-frnf, ad"T 3f{ m firf, d=q qrfi { Sd dx {d rs d I Erg ftt gf,fl { T{fi ffiRrd
Et6q $d ti mr qRrdq atTil
A concave mirror and a convex lens are dipped in water. What will be change in
their focal length in comparison to that of in air?

42e (rGU) t6l

23 ' qfr ffi s-6TeI +iT e #Pils qq 3lrqfud r6ler bt sTgfr g$" A Hre
-"c"'oo v'r\rr* fr ftrq fus ror
L'r
qfffidp".if
' 3
(i) Fe-qiq)#rrfrHg-df
($i) s-6tET fua unr
(iii) FrS€fr fu{d
smS aa'q m} mrm* mlfrur
trf the freguemcy of incldent light
on the cathode of photocell is doubled
then how
will the following change :
(i) Kinetic energy of electrons
(,i) Fhotoeieetric current
{i[i) Stoppingpotentiat
")ust!fy you r a!-lswer.

24' rm"qm *iw.' & w'mr & wq tt sft qfuqr{ qem
rsf a, qrw dfu apn $sfls& fu sfr
qfuqm Bi€ffis.frf ffi qrftro e RlTfuq fr mrswq
Drau; the graph of binding energy per
tp g
nucleon as a function of mass number
and
explain what is the relation of binding energy
per nucleon with stability of nucleus?

sTerqr79p
ETFr6?q ffnqq fr oo 6rs-#rE * o.ggs q.rq fifuqq srq +fr crfr
] dr Hfu* # aerar
5o1o d d *qs sat d rrurqr
ffiuf
0"993 grn helium is produced by 19m
hydrogen in nuclear fusion. If the efficiency
of generator is 570 then carcurate the energy
produced.
2s. rvAr\D dem NoR,)e or d# rfr6 dfus il.Tr
Frd H?qqH sRoft *Hdr 3
Draw the logic symbor of NAND and NoR gate
and give their truth tabre.

SreEII/OR
p-n qRr s+s or sqfrT 6Tb
d-rdrsil b r$r sqt d c+ri g
[uf il$r M o.r qRqq 3Trtg d}frsr fr]* 3rt{
fufd
Fsot frq-ftfu squr$+r
Dnaw circuit diagram of full wave
rectifier by using p-n junction diode.
Explain it,s
wonking by drawing input and output
vortage waveforms.

42e (tcu)
t7l lP.T.O.

26. {d-rq qfrqu ti p aw a & &{ frq-dra{ aen frF{s qftrtsn fr lnrBa tr{Eit b rTH f,rf,
frtu1 4

In the figure, find potential difference between P and Q" Also find currents flowing
in different resistances.
2.4 A
4a tr 10f)
P

i2 4o

i2 a
9f)
3{erir[/OR
qlffi t-g 6T ftrdm errsigdr sqd varirdr t ffi
eTrE b dR o't qfr-ttr t* sro mttt
qgm
SF 6l furrr{ dBrst
eive piinciple of meter bridge. How will you find resistance of a metallic wire
with the help of it. Derive the formula used.

zz. EffiTsptduoffi-{qrFrdbdrii siX e .e xr0=fi/tb Et zn tr-ffifroem
+ qF *6r"dt +nb E# fu- €iKI der,i sstb g-s g,seiq sTryt fr Tor+r #fu1 {
of radius 0.7d
In an atom, an electron is revolving round the nucleus in an orbit
witli the velocity of 6.6x 104 m/s. Find the equivalent current and the equivalent
magnetic moment.
3{srEr/oR
drq\-tr or fru+ dd rfli I trflroT{ €n<rdrfi qq & b< q< rcr+ gry61q et{ d fronr mt
aisdr qrq 6Gsr
Give Biot-Savart law. Find an expression for intensity of magnetic field at the
centre of current carrying circular loop.
zB. A-rH Frqf* {d b ftrd FFr dinn %eqq d}fHs, sd Hffiib s_dftrd 3{Pf d-
4
Derive the ibltowing expression for lens maker formula, where symbols have
their usual meanings-
1 .(t
^=(n-1)l-:-- 1)
-
f '(R, RrJ
I

3Terdry/gp

t
Eeq-6 a{ftffiBii mq ffir HqflA da amr< b kfiq6 il{ftoT3ii b fudr< b sTI€rK
qr q<rf,{q d qrsr frHut
What do you understand by secondary wavelets? Explain the reflection on the
basis of Huygen's secondary wavelets principle.

42e(tGU) t8l