Class 12 Question Paper 2023 Physics

ANNUAL EXAMINATION

Question Paper
2023

NCERT BASED SYLLABUS
FOR CBSE AND STATE BOARD
FOLLOWING NCERT

Series GEFH1/1 SET~1
àíZ-nÌ H$moS>
amob Z§. Q.P. Code 55/1/1
Roll No.
narjmWu àíZ-nÌ H$moS> >H$mo CÎma-nwpñVH$m Ho$
_wI-n¥ð >na Adí` {bIo§ &
Candidates must write the Q.P. Code
on the title page of the answer-book. *

^m¡{VH$ {dkmZ (g¡ÕmpÝVH$)
PHYSICS (Theory)
:3 : 70
Time allowed : 3 hours Maximum Marks : 70
ZmoQ> / NOTE :
(i) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _o§ _w{ÐV n¥ð> 27 h¢ &
Please check that this question paper contains 27 printed pages.
(ii) àíZ-nÌ _| Xm{hZo hmW H$s Amoa {XE JE àíZ-nÌ H$moS> H$mo narjmWu CÎma-nwpñVH$m Ho$ _wI-n¥ð> na
{bI| &
Q.P. Code given on the right hand side of the question paper should be written
on the title page of the answer-book by the candidate.
(iii) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _| >35 àíZ h¢ &
Please check that this question paper contains 35 questions.
(iv) H¥$n`m àíZ H$m CÎma {bIZm ewê$ H$aZo go nhbo, CÎma-nwpñVH$m _| àíZ H$m H«$_m§H$ Adí`
{bI| &
Please write down the serial number of the question in the
answer-book before attempting it.
(v) Bg àíZ-nÌ 15 {_ZQ >H$m g_` {X`m J`m h¡ & àíZ-
10.15 ~Oo {H$`m OmEJm & 10.15 ~Oo go 10.30 ~Oo VH$ N>mÌ Ho$db àíZ-
Ad{Y Ho$ Xm¡amZ do CÎma-nwpñVH$m na H$moB© CÎma Zht {bI|Jo &
15 minute time has been allotted to read this question paper. The question

paper will be distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the
students will read the question paper only and will not write any answer on the
answer-book during this period.

55/1/1 Page 1 of 27 P.T.O.

:

:
(i) 35
(ii)
(iii) 1 18 (MCQ)
(iv) 19 25 (VSA)

(v) 26 30 (SA)
(vi) 31 33 (LA)
(vii) 34 35
(viii) 2 2
3 2

(ix)
:
c=3 108 m/s
h = 6.63 10 34 Js
e = 1.6 10 19 C

0=4 10 7 T m A 1
. 10 12 C2 N 1 m 2
0 = 8 854
1
=9 109 N m2 C 2
4
0

(me) = 9.1 10 31 kg

Ý`yQ´>m°Z H$m Ðì`_mZ = 1.675 10 27 kg
àmoQ>m°Z H$m Ðì`_mZ = 1.673 10 27 kg

AmdmoJmÐmo g§»`m = 6.023 1023 à{V J«m_ _mob (per gram mole)
~moëQ²>µO_mZ {Z`Vm§H$ = 1.38 10 23 JK 1

55/1/1 Page 2 of 27

General Instructions :
Read the following instructions very carefully and strictly follow them :
(i) This question paper contains 35 questions. All questions are compulsory.
(ii) This question paper is divided into five Sections A, B, C, D and E.
(iii) In Section A Questions no. 1 to 18 are Multiple Choice (MCQ) type
questions, carrying 1 mark each.
(iv) In Section B Questions no. 19 to 25 are Very Short Answer (VSA) type
questions, carrying 2 marks each.
(v) In Section C Questions no. 26 to 30 are Short Answer (SA) type questions,
carrying 3 marks each.
(vi) In Section D Questions no. 31 to 33 are Long Answer (LA) type questions
carrying 5 marks each.
(vii) In Section E Questions no. 34 and 35 are case-based questions carrying
4 marks each.
(viii) There is no overall choice. However, an internal choice has been provided in
2 questions in Section B, 2 questions in Section C, 3 questions in Section D and
2 questions in Section E.
(ix) Use of calculators is not allowed.
Use the following values of physical constants, if required :
c=3 108 m/s
h = 6.63 10 34 Js
e = 1.6 10 19 C

0=4 10 7 T m A 1

0 = 8 854
. 10 12 C2 N 1 m 2
1
=9 109 N m2 C 2
4
0

Mass of electron (me) = 9.1 10 31 kg

Mass of neutron = 1.675 10 27 kg
Mass of proton = 1.673 10 27 kg

6.023 1023 per gram mole
Boltzmann constant = 1.38 10 23 JK 1

55/1/1 Page 3 of 27 P.T.O.

IÊS> H$
1. {H$gr bKw {dÚwV {ÛY«wd Ho$ Aj na Cggo Xÿar na pñWV H$moB© {~ÝXþ Amdoe F ~b H$m
AZw^d H$aVm h¡ & `{X Amdoe H$s Xÿar h¡, Vmo Amdoe Ûmam AZw^d {H$`m OmZo dmbm
~b hmoJm :
F F F F
(a) (b) (c) (d)
16 8 4 2

2. {H$gr YmpËdH$ MmbH$ Ho$ {bE, Vmn T Ho$ gmW à{VamoY R Ho$ ghr {dMaU H$mo {Zê${nV
H$aZo dmbm J«m\$ h¡ :

(a) (b) (c) (d)

3. {H$gr Iwbo n[anW _| {H$gr gob Ho$ {gam| Ho$ ~rM {d^dmÝVa 8 V h¡ & O~ Bg gob go 4 A
Ymam br OmVr h¡ Vmo {d^dmÝVa KQ>H$a 4 V hmo OmVm h¡ & Bg gob H$m AmÝV[aH$ à{VamoY h¡ :
(a) 4 (b) 3 (c) 2 (d) 1

4. {H$gr YmVw Ho$ Vma, {OgH$s AZwàñW-H$mQ> H$m joÌ\$b (A) EH$ {gao go Xÿgao {gao VH$
A Ho$ \$bZ Ho$ ê$n _| _wº$
(vd) Ho$ n[a_mU H$mo Xem©`m Om gH$Vm h¡ : $

(a) (b) (c) (d)

5. Y«wd Ho$ {ZH$Q> bm`m
J`m h¡ & `h nXmW© :
(a) XmoZm| Y«wdm| Ûmam à{VH${f©V {H$`m OmEJm &

(b) XmoZm| Y«wdm| Ûmam AmH${f©V {H$`m OmEJm &
(c) CÎma Y«wd Ûmam à{VH${f©V VWm X{jU Y«wd Ûmam AmH${f©V {H$`m OmEJm &$
(d) CÎma Y«wd Ûmam AmH${f©V VWm X{jU Y«wd Ûmam à{VH${f©V {H$`m OmEJm &$
55/1/1 Page 4 of 27

SECTION A

1.
axis, experiences a force F
on the charge will be :
F F F F
(a) (b) (c) (d)
16 8 4 2

2. For a metallic conductor, the correct representation of variation of
resistance R with temperature T is :

(a) (b) (c) (d)

3. The potential difference across a cell in an open circuit is 8 V. It falls to
4 V when a current of 4 A is drawn from it. The internal resistance of the
cell is :
(a) 4 (b) 3 (c) 2 (d) 1

4. A steady current flows through a metallic wire whose area of
cross-section (A) increases continuously from one end of the wire to the
other. The magnitude of drift velocity (vd) of the free electrons as a

(a) (b) (c) (d)

5. A diamagnetic substance is brought near the north or south pole of a bar
magnet. It will be :

(a) repelled by both the poles.
(b) attracted by both the poles.
(c) repelled by the north pole and attracted by the south pole.
(d) attracted by the north pole and repelled by the south pole.
55/1/1 Page 5 of 27 P.T.O.

6. H$moB© d¥ÎmmH$ma Hw$ÊS>br {OgH$s {ÌÁ`m 8·0 cm h¡ VWm {Og_| 40 \o$ao h¢, AnZo D$Üdm©Ya ì`mg
Ho$ n[aV: 25 ao{S>`Z à{V goH$ÊS> H$s H$moUr` Mmb go 3·0 10 2 T n[a_mU Ho$ {H$gr
EH$g_mZ j¡{VO Mwå~H$s` joÌ _| KyU©Z H$a ahr h¡ & Bg Hw$ÊS>br _| ào[aV A{YH$V_
{d.dm. ~b (emf ) h¡ :
(a) 0·12 V (b) 0·15 V
(c) 0·19 V (d) 0·22 V

7. AmaoI _| {H$gr Am`VmH$ma MmbH$ PSRQ H$mo Xem©`m J`m h¡ {Og_| J{V_mZ ^wOm PQ H$m
à{VamoY h¡ VWm PSRQ H$m à{VamoY CnojUr` h¡ & O~ PQ H$mo doJ v go J{V H$amB© OmVr
h¡ Vmo ào[aV {d.dm. ~b (emf ) H$m n[a_mU {ZåZ{b{IV _| go {H$g na {Z^©a H$aVm h¡ ?

(a) Mwå~H$s` joÌ ( B ) $ (b) doJ ( v )
(c) à{VamoY (r) > (d) PQ H$s bå~mB©

8. {H$gr g§Ym[aÌ H$mo Amdo{eV H$aZo H$s à{H«$`m _|, g§Ym[aÌ H$s n{Å>H$mAm| Ho$ ~rM CËnÞ
{dÚwV Ymam hmoVr h¡ :
d E 1 d E
(a) 0 (b)
dt 0 dt
d E 1 d E
(c) 0 (d)
dt 0 dt
`hm± àVrH$m| Ho$ gm_mÝ` AW© h¢ &

9. \$moH$g Xÿar f Ho$ {H$gr AdVb Xn©U Ho$ {bE {~å~ Am¡a CgHo$ dmñV{dH$ à{V{~å~ Ho$

~rM H$s Ý`yZV_ Xÿar hmoVr h¡ :
(a) eyÝ` (b) f

(c) 2f (d) 4f
55/1/1 Page 6 of 27

6. A circular coil of radius 8 0 cm and 40 turns is rotated about its vertical
25
diameter with an angular speed of rad s 1 in a uniform horizontal

magnetic field of magnitude 3 0 10 2 T. The maximum emf induced in
the coil is :
(a) 0·12 V (b) 0·15 V $
(c) 0·19 V (d) 0·22 V

7. Figure shows a rectangular conductor PSRQ in which movable arm PQ

of emf induced when PQ is moved with a velocity v does not depend on :

(a) magnetic field ( B ) (b) velocity ( v )
(c) resistance (r) (d) length of PQ

8. In the process of charging of a capacitor, the current produced between
the plates of the capacitor is :
d E 1 d E
(a) 0 (b)
dt 0 dt

d E 1 d E
(c) 0 (d)
dt 0 dt
where symbols have their usual meanings.

9. f

the object and its real image is :
(a) zero (b) f
(c) 2f (d) 4f
55/1/1 Page 7 of 27 P.T.O.

10. hmBS´>moOZ na_mUw Ho$ ~moa _m°S>b _| ndt H$jm H$s {ÌÁ`m {ZåZ{b{IV _| go {H$gHo$
g_mZwnmVr hmoVr h¡ ?
1 1
(a) (b)
n2 n
(c) n2 (d) n

11. hmBS´>moOZ na_mUw AnZr Amapå^H$ {ZåZV_ AdñWm _| {H$gr \$moQ>m°Z H$mo Ademo{fV H$aVm h¡
Omo Cgo n = 5 ñVa VH$ CÎmo{OV H$a XoVm h¡ & Bg \$moQ>m°Z H$s Va§JX¡Ü`© h¡ :
(a) 975 nm (b) 740 nm
(c) 523 nm (d) 95 nm

12. Ðì`_mZ g§»`m A Ho$ Zm{^H$ H$m Ðì`_mZ KZËd :
(a) A1 / 3 Ho$ g_mZwnmVr hmoVm h¡ $
(b) A 2 / 3 Ho$ g_mZwnmVr hmoVm h¡
3
(c) A Ho$ g_mZwnmVr hmoVm h¡
(d) A na {Z^©a Zht H$aVm h¡

13. dmoëQ>oO H$m H$moB© ac òmoV loUr _| {H$gr p-n g§{Y S>m`moS> Am¡a bmoS> à{VamoYH$ go g§`mo{OV
h¡ & bmoS> à{VamoY Ho$ {gam| na {ZJ©V dmoëQ>Vm Ho$ {bE ghr {dH$ën hmoJm :

55/1/1 Page 8 of 27

10. The radius of the nth orbit in Bohr model of hydrogen atom is
proportional to :
1 1
(a) (b)
n2 n

(c) n2 (d) n

11. Hydrogen atom initially in the ground state, absorbs a photon which
excites it to n = 5 level. The wavelength of the photon is :
(a) 975 nm (b) 740 nm
(c) 523 nm (d) 95 nm

12. The mass density of a nucleus of mass number A is :

(a) proportional to A1 / 3

(b) proportional to A 2 / 3

(c) proportional to A3

(d) independent of A

13. An ac source of voltage is connected in series with a p-n junction diode
and a load resistor. The correct option for output voltage across load
resistance will be :

55/1/1 Page 9 of 27 P.T.O.

14. O~ {H$gr Z¡O AY©MmbH$ H$mo {H$gr {Ìg§`moOr Aew{Õ H$s Aën _mÌm go _m{XV {H$`m OmVm
h¡, Vmo :
(a) &
(b) `h p-àH$ma H$m AY©MmbH$ ~Z OmVm h¡ &
(c) Cg AY©
(d) _mXH$ (An{_lH$) na_mUw XmVm na_mUw ~Z OmVo h¢ &

15. n-àH$ma Ho$ Si Ho$ D$Om©-~¡ÊS> AmaoI _|, MmbZ ~¡ÊS> H$s Vbr EC Am¡a XmVm D$Om© ñVa ED
Ho$ ~rM AÝVamb H$s H$mo{Q> hmoVr h¡ :
(a) 10 eV

(b) 1 eV

(c) 0·1 eV

(d) 0·01 eV

16 18 (A) (R)
(A) (R)
(a), (b), (c) (d)
(a) A{^H$WZ (A) Am¡a H$maU (R) XmoZm| ghr h¢ Am¡a H$maU (R), A{^H$WZ (A) H$s
ghr ì¶m»¶m H$aVm h¡ &
(b) A{^H$WZ (A) Am¡a H$maU (R) XmoZm| ghr h¢, naÝVw H$maU (R), A{^H$WZ (A) H$s
ghr ì¶m»¶m H$aVm h¡ &
(c) A{^H$WZ (A) ghr h¡, naÝVw H$maU (R) µJbV h¡ &
(d) A{^H$WZ (A) µJbV h¡ VWm H$maU (R) ^r µJbV h¡ &

16. (A) : Mwå~H$s` joÌ _| aIm OmVm h¡,

(R) : H$m°na EH$ AZwMwå~H$s` nXmW© h¡ &

55/1/1 Page 10 of 27

14. When an intrinsic semiconductor is doped with a small amount of
trivalent impurity, then :
(a) its resistance increases.
(b) it becomes a p-type semiconductor.
(c) there will be more free electrons than holes in the semiconductor.
(d) dopant atoms become donor atoms.

15. In the energy-band diagram of n-type Si, the gap between the bottom of
the conduction band EC and the donor energy level ED is of the order of :

(a) 10 eV
(b) 1 eV

(c) 0 1 eV
(d) 0 01 eV

Questions number 16 to 18 are Assertion (A) and Reason (R) type questions. Two
statements are given one labelled Assertion (A) and the other labelled Reason
(R). Select the correct answer from the codes (a), (b), (c) and (d) as given below.
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the
correct explanation of the Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not
the correct explanation of the Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false and Reason (R) is also false.

16. Assertion (A) : When a bar of copper is placed in an external magnetic

field, the field lines get concentrated inside the bar.

Reason (R) : Copper is a paramagnetic substance.

55/1/1 Page 11 of 27 P.T.O.

17. (A) : {H$gr Va§JmJ« Ho$ {H$Ýht Xmo {~ÝXþAm| Ho$ ~rM H$bmÝVa eyÝ` hmoVm h¡ &
(R) : {H$gr Va§JmJ« Ho$ g^r {~ÝXþ òmoV go g_mZ Xÿar na hmoVo h¢ Am¡a Bg àH$ma
g_mZ H$bm _| XmobZ H$aVo h¢ &

18. (A) : àH$me-{dÚwV à^md àH$me H$s H$UmË_H$ àH¥${V H$mo {ZX{e©V H$aVm h¡ &
(R) : Xohbr Amd¥{Îm go A{YH$ Amd¥{Îm`m| Ho$ {bE àH$me-{dÚwV Ymam Amn{VV
{d{H$aUm| H$s Vrd«Vm Ho$ g_mZwnmVr hmoVr h¡ &

IÊS> I
19. {H$gr Eoë\$m H$U H$mo doJ v = (3·0 105 m/s) ^i go Cg joÌ _| àjo{nV {H$`m J`m h¡
{Og_| H$moB© Mwå~H$s` joÌ B = [(0·4 T) ^i + (0·3 T) ^j ] {dÚ_mZ h¡ & Bg joÌ _| H$U
H$m ËdaU n[aH${bV H$s{OE & ^i , ^j Am¡a ^k H«$_e: x, y Am¡a z Aj Ho$ AZw{Xe EH$m§H$
g{Xe h¢ VWm Eoë\$m H$U Ho$ {bE Amdoe Am¡a Ðì`_mZ AZwnmV 4·8 107 C/kg h¡ & 2

20. {H$gr n[adVu {dÚwV joÌ Ho$ H$maU ào[aV Mwå~H$s` joÌ Am¡a n[adVu Mwå~H$s` joÌ Ho$
H$maU ào[aV {dÚwV joÌ na {dMma H$s{OE & BZ_| go {H$gH$m àojU A{YH$ AmgmZr go {H$`m
Om gH$Vm h¡ ? AnZo CÎma H$s nw{îQ> H$s{OE & 2

21. (H$) hmBJ|g {gÕmÝV H$m Cn`moJ H$aHo$ {H$gr g_Vb Va§J H$m {H$gr Xmo _mÜ`_m| H$mo
n¥WH$ H$aZo dmbo g_Vb n¥îR> na AndV©Z Xem©Zo dmbm {H$aU AmaoI It{ME &
AndV©Z Ho$ ñZob Ho$ {Z`_ H$m gË`mnZ ^r H$s{OE & 2

AWdm
(I) AndVu XÿaXe©H$ H$s VwbZm _| namdVu XÿaXe©H$ H$mo àmW{_H$Vm ? Xmo

H$maU XoVo hþE AnZo CÎma H$s nw{îQ> H$s{OE & 2

55/1/1 Page 12 of 27

17. Assertion (A) : The phase difference between any two points on a
wavefront is zero.

Reason (R) : All points on a wavefront are at the same distance from
the source and thus oscillate in the same phase.

18. Assertion (A) : Photoelectric effect demonstrates the particle nature of
light.
Reason (R) : Photoelectric current is proportional to intensity of
incident radiation for frequencies more than the threshold
frequency.

SECTION B

^
19. An alpha particle is projected with velocity v = (3·0 105 m/s) i into a
^ ^
region in which magnetic field B = [(0·4 T) i + (0·3 T) j ] exists.
^ ^ ^
Calculate the acceleration of the particle in the region. i , j and k are

unit vectors along x, y and z axis respectively and charge to mass ratio
for alpha particle is 4·8 107 C/kg. 2

20. Consider an induced magnetic field due to changing electric field and an
induced electric field due to changing magnetic field. Which one is more
easily observed ? Justify your answer. 2

21. (a)
propagation of a plane wave refracting at a plane surface
separating two media. 2
OR

(b) Why is a reflecting telescope preferred over a refracting telescope ?
Justify your answer giving two reasons. 2

55/1/1 Page 13 of 27 P.T.O.

22. I Am¡a 4 I Vrd«VmAm| Ho$ Xmo EH$dUu H$bmg§~Õ àH$me nwÝO EH$-Xÿgao na AÜ`mamonU H$aVo
h¢ & n[aUm_r nwÝO _| A{YH$V_ Am¡a Ý`yZV_ Vrd«VmAm| H$m AZwnmV kmV H$s{OE & 2

23. hmBS´>moOZ na_mUw H$s {ZåZV_ D$Om© AdñWm 13·6 eV h¡ & V¥Vr` CÎmo{OV AdñWm _|
? 2

24. (H$) Z¡O Am¡a AnÐì`r AY©MmbH$m| Ho$ ~rM {d^oXZ H$s{OE & 2
AWdm
(I) AJ«{X{eH$ ~m`g Am¡a níM{X{eH$ ~m`g _| {H$gr p-n g§{Y S>m`moS> Ho$ V I
A{^bmj{UH$m| H$m AÜ``Z H$aZo Ho$ {bE n[anW ì`dñWm It{ME & {g{bH$m°Z
S>m`moS> Ho$ V I A{^bmj{UH$ H$m AmboI àX{e©V H$s{OE & 2

25. g§jon _| ì`m»`m H$s{OE {H$ {H$gr p-n g§{Y S>m`moS> _| {dgaU Am¡a Andmh YmamE± {H$g
àH$ma amo{YH$m {d^d Ho$ {Z_m©U _| `moJXmZ H$aVr h¢ & 2

IÊS> J

26. (H$) AmaoI (i) _| Xem©E AZwgma R {ÌÁ`m Ho$ {H$gr d¥Îm H$s n[a{Y na g_mZ Xÿ[a`m| na
g_mZ n[a_mU Ho$ 12 G$Umdoe pñWV h¢ & AZÝV na eyÝ` {d^d Ho$ gmnoj d¥Îm Ho$
Ho$ÝÐ C na {dÚwV {d^d Am¡a {dÚwV joÌ kmV H$s{OE &
(I) `{X AmaoI (ii) _| Xem©E AZwgma Amdoe {ÌÁ`m R Ho$ 120 Ho$ Mmn na Ag_mZ
Xÿ[a`m| na pñWV h¢, Vmo Ho$ÝÐ C na {dÚwV {d^d kmV H$s{OE & 3

(i) (ii)

55/1/1 Page 14 of 27

22. Two coherent monochromatic light beams of intensities I and 4 I
superpose each other. Find the ratio of maximum and minimum
intensities in the resulting beam. 2

23. The ground state energy of hydrogen atom is 13 6 eV. What is the
potential energy and kinetic energy of an electron in the third excited
state ? 2

24. (a) Differentiate between intrinsic and extrinsic semiconductors. 2
OR
(b) Draw the circuit arrangement for studying the V I characteristics
of a p-n junction diode in forward bias and reverse bias. Show the
plot of V I characteristic of a silicon diode. 2

25. Briefly explain how the diffusion and drift currents contribute to the
formation of potential barrier in a p-n junction diode. 2

SECTION C

26. (a) Twelve negative charges of same magnitude are equally spaced and
fixed on the circumference of a circle of radius R as shown in Fig. (i).
Relative to potential being zero at infinity, find the electric potential
and electric field at the centre C of the circle.
(b) If the charges are unequally spaced and fixed on an arc of 120 of
radius R as shown in Fig. (ii), find electric potential at the centre C. 3

(i) (ii)

55/1/1 Page 15 of 27 P.T.O.

27. (H$) à{VamoY {H$g àH$ma à{V~mYm go {^Þ h¡ ? Cn`wº$ \o$µOa AmaoI H$s ghm`Vm go {H$gr
loUr LCR n[anW, Omo {H$gr òmoV v = vm sin t go g§`mo{OV h¡, H$s à{V~mYm Ho$
{bE ì`§OH$ àmßV H$s{OE & 3
AWdm
(I) òmoV v = vm sin t, {Og_| H$mo n[ad{V©V {H$`m Om gH$Vm h¡, go g§`mo{OV {H$gr
loUr LCR n[anW Ho$ AZwZmX Ho$ {bE eV© kmV H$s{OE & CZ H$maH$m| H$m CëboI
H$s{OE {OZ na {H$gr loUr LCR n[anW H$s AZwZmX Amd¥{Îm {Z^©a H$aVr h¡ &
{H$gr loUr LCR n[anW _| Amd¥{Îm Ho$ gmW {dÚwV Ymam Ho$ {dMaU H$mo Xem©Zo Ho$
{bE J«m\$ It{ME & 3

28. {ÌÁ`m r H$s {H$gr bå~r n[aZm{bH$m _| à{V EH$m§H$ bå~mB© _| \o$am| H$s g§»`m n h¡ & Bg
n[aZm{bH$m _| àdm{hV Ymam I = I0 sin t h¡ & BgHo$ Ho$ÝÐ Ho$ {ZH$Q> BgHo$ Mmam| Amoa
N \o$am| H$s H$moB© Hw$ÊS>br H$g H$a {bnQ>r h¡ &
(H$) Hw$ÊS>br _| ào[aV {d.dm. ~b (emf) ?
(I) ? 3

29. AmB§ñQ>mBZ H$m àH$me-{dÚwV gO©Z H$s ì`m»`m
{H$g àH$ma H$aVm h¡ ? g§jon _| ì`m»`m H$s{OE &
(H$) Amn{VV {d{H$aUm| H$s {d{^Þ Vrd«VmAm| Ho$ {bE àH$me-{dÚwV Ymam H$m g§J«mhH$
ßboQ> {d^d Ho$ gmW {dMaU J«m\$ ItMH$a Xem©BE, VWm
(I) Amn{VV {d{H$aUm| H$s Vrd«Vm Ho$ gmW àH$me-{dÚwV Ymam Ho$ {dMaU H$mo Xem©Zo Ho$
{bE J«m\$ It{ME & 3

30. (H$) hmBS´>moOZ na_mUw Ho$ {bE D$Om© ñVa AmaoI It{ME & nam~¢JZr joÌ, Ñí` joÌ Am¡a
Adaº$ joÌ H$s lo{U`m| Ho$ VXZwê$n g§H«$_Um| H$mo A§{H$V H$s{OE & 3

AWdm
(I) {d{^Þ Zm{^H$m| Ho$ {bE Ðì`_mZ g§»`m Ho$ Ho$
{dMaU H$mo Xem©Zo Ho$ {bE AmaoI It{ME Am¡a BgH$s Xmo {deofVmAm| H$m CëboI

H$s{OE & hëHo$ Zm{^H$m| _| àm`: ? 3

55/1/1 Page 16 of 27

27. (a) How does the resistance differ from impedance ? With the help of a
suitable phasor diagram, obtain an expression for impedance of a
series LCR circuit, connected to a source v = vm sin t. 3
OR

(b) Find the condition for resonance in a series LCR circuit connected
to a source v = vm sin t, where can be varied. Give the factors on
which the resonant frequency of a series LCR circuit depends. Plot
a graph showing the variation of electric current with frequency in
a series LCR circuit. 3

28. A long solenoid of radius r consists of n turns per unit length. A current
I = I0 sin t flows in the solenoid. A coil of N turns is wound tightly
around it near its centre. What is :
(a) the induced emf in the coil ?
(b) the mutual inductance between the solenoid and the coil ? 3

29.
electrons from a metal surface ? Explain briefly.
Plot the variation of photocurrent with :
(a) collector plate potential for different intensity of incident radiation,
and
(b) intensity of incident radiation. 3

30. (a) Draw the energy level diagram for hydrogen atom. Mark the
transitions corresponding to the series lying in the ultraviolet
region, visible region and infrared region. 3
OR

(b) Draw a diagram to show the variation of binding energy per
nucleon with mass number for different nuclei and mention its two
features. Why do lighter nuclei usually undergo nuclear fusion ? 3

55/1/1 Page 17 of 27 P.T.O.

IÊS> K

31. (H$) (i) pñWa-d¡Úw{VH$s _| Hy$bm°_ {Z`_ H$m CëboI H$s{OE Am¡a Bgo Xmo Amdoem| Ho$
{bE g{Xe ê$n _| {b{IE &
(ii) JmCg {Z`_ Hy$bm°_ {Z`_ _| gpå_{bV Xÿar Ho$ dJ© Ho$ ì`wËH«$_mZwnmV na
AmYm[aV h¡ & ì`m»`m H$s{OE &
(iii) Xmo Amdoe A (Amdoe q) VWm B (Amdoe 2q) H«$_e: {~ÝXþAm| (0, 0) Am¡a
(a, a) na pñWV h¢ & _mZ br{OE x-Aj Am¡a y-Aj Ho$ AZw{Xe EH$m§H$
g{Xe H«$_e: ^i Am¡a ^j h¢ & ^i Am¡a ^j Ho$ nXm| _| A H$m B na Amamo{nV
~b kmV H$s{OE & 5

AWdm
(I) (i) 2a Xÿar Ho$ n¥WH$Z dmbo Xmo Amdoem| q Am¡a q Ho$ ~Zo {H$gr {dÚwV {ÛY«wd
Ho$ {Zajr` g_Vb Ho$ {H$gr {~ÝXþ na {dÚwV joÌ Ho$ {bE ì`§OH$ ì`wËnÞ
H$s{OE &
(ii) {H$gr {dÚwV {ÛY«wd Ho$ {Zajr` g_Vb na pñWV {H$gr XÿañW {~ÝXþ H$s Xÿar
AmYr H$a Xr JB© h¡ & Bg {ÛY«wd Ho$ {bE {dÚwV joÌ {H$g àH$ma à^m{dV
hmoJm ?
(iii) AmaoI _| Xem©E AZwgma {H$gr 2 m ^wOm Ho$ dJ© ABCD Ho$ {dH$Um] Ho$
AZw{Xe Xmo gd©g_ {dÚwV {ÛY«wd aIo h¢ & Bg dJ© Ho$ Ho$ÝÐ (O) na ZoQ>
{dÚwV joÌ H$m n[a_mU Am¡a {Xem àmßV H$s{OE & 5

55/1/1 Page 18 of 27

SECTION D

31. (a) (i)
form, for two charges.

(ii) -square dependence on
di

(iii) Two charges A (charge q) and B (charge 2q) are located at
^ ^
points (0, 0) and (a, a) respectively. Let i and j be the unit
vectors along x-axis and y-axis respectively. Find the force
^ ^
exerted by A on B, in terms of i and j . 5

OR

(b) (i) Derive an expression for the electric field at a point on the
equatorial plane of an electric dipole consisting of charges q
and q separated by a distance 2a.

(ii) The distance of a far off point on the equatorial plane of an
electric dipole is halved. How will the electric field be affected
for the dipole ?

(iii) Two identical electric dipoles are placed along the diagonals of
a square ABCD of side 2 m as shown in the figure. Obtain
the magnitude and direction of the net electric field at the
centre (O) of the square. 5

55/1/1 Page 19 of 27 P.T.O.

32. (H$) (i) {H$gr Ymamdmhr Ad`d Ho$ H$maU Mwå~H$s` joÌ Ho$ {bE ~m`mo-gmdQ>© {Z`_
{b{IE & Bg {Z`_ H$m Cn`moJ H$aHo$ {ÌÁ`m Ho$ {H$gr d¥ÎmmH$ma nme,
{Oggo Ymam àdm{hV hmo ahr h¡, Ho$ Ho$ÝÐ na Mwå~H$s` joÌ Ho$ {bE H$moB©
ì`§OH$ àmßV H$s{OE & {H$gr Ymam nme Ho$ {bE Mwå~H$s` joÌ H$s {Xem H$mo
B§{JV H$aVo hþE Mwå~H$s` joÌ aoImE± It{ME &
(ii) 107 m s 1 H$s Mmb go

n[aH«$_m H$a ahm h¡ & `{X H$jm H$s {ÌÁ`m 10 10 m h¡, Vmo H$jm _|
5

AWdm
(I) (i) Mwå~H$s` joÌ _| pñWV {H$gr Ymamdmhr grYo MmbH$ na H$m`©aV ~b Ho$
{bE ì`§OH$ ì`wËnÞ H$s{OE & Cg {Z`_ H$m CëboI H$s{OE Omo Bg ~b
H$s {Xem H$mo {ZYm©[aV H$aZo Ho$ {bE Cn`moJ {H$`m OmVm h¡ & dh eV© Xr{OE
{OgHo$ A§VJ©V `h ~b (1) A{YH$V_, Am¡a (2) {ZåZV_ hmoVm h¡ &

(ii) Xmo bå~o grYo g_mÝVa Vma A Am¡a B dm`w _| EH$-Xÿgao go 2·5 cm Xÿar na
h¢ & BZ Vmam| go {dnarV {XemAm| _| H«$_e: 5·0 A Am¡a 2·5 A YmamE±
àdm{hV hmo ahr h¢ & Vma B H$s 10 cm bå~mB© na Vma A Ûmam Amamo{nV ~b
H$m n[a_mU n[aH${bV H$s{OE & 5

33. (H$) (i) (1) ì`{VH$aU n¡Q>Z© Am¡a {ddV©Z n¡Q>Z© Ho$ ~rM Xmo AÝVa {b{IE &

(2) `§J Ho$ {Û{Par à`moJ _| {H$Ýht Xmo H$maH$m| Ho$ Zm_ {b{IE {OZ na
q\

55/1/1 Page 20 of 27

32. (a) (i) State Biot-
carrying element. Use this law to obtain an expression for the

current loop indicating the direction of magnetic field.

(ii) An electron is revolving around the nucleus in a circular orbit
7 10
with a speed of 10 m s 1. If the radius of the orbit is 10 m,
find the current constituted by the revolving electron in the
orbit. 5

OR

(b) (i) Derive an expression for the force acting on a current carrying
straight conductor kept in a magnetic field. State the rule
which is used to find the direction of this force. Give the
condition under which this force is (1) maximum, and
(2) minimum.

(ii) Two long parallel straight wires A and B are 2 5 cm apart in
air. They carry 5 0 A and 2 5 A currents respectively in
opposite directions. Calculate the magnitude of the force
exerted by wire A on a 10 cm length of wire B. 5

33. (a) (i) (1) Write two points of difference between an interference
pattern and a diffraction pattern.

(2) Name any two factors on which the fringe width in a
-slit experiment depends.

55/1/1 Page 21 of 27 P.T.O.

(ii) `§J Ho$ {H$gr {Û{Par à`moJ _| Xmo {P[a`m| Ho$ ~rM n¥WH$Z {P[a`m| go Jw µOaZo
dmbo àH$me H$s Va§JX¡Ü`© H$m 100 JwZm h¡ &
(1)
ao{S>`Zm| _| n[aH$bZ H$s{OE &

(2) {P[a`m| go 50 cm Ho$ _Ü`
Xÿar n[aH${bV H$s{OE & 5

AWdm
(I) (i) dH«$Vm {ÌÁ`m R H$m H$moB© Jmobr` n¥îR> n1 Am¡a n2 AndV©Zm§H$m| Ho$ Xmo
_mÜ`_m| H$mo EH$-Xÿgao go n¥WH$ H$aVm h¡ & n1 AndV©Zm§H$ Ho$ _mÜ`_ _|
H$moB© {~ÝXþ{H$V {~å~ Bg n¥îR> go Xÿar u na aIm h¡ Am¡a n¥îR> Ûmam BgH$m
à{V{~å~ n2 AndV©Zm§H$ Ho$ _mÜ`_ _| n¥îR> go v Xÿar na ~Z ahm h¡ & u
Am¡a v Ho$ ~rM g§~§Y ì`wËnÞ H$s{OE &

(ii) AmaoI _| Xem©E AZwgma 6·0 cm {ÌÁ`m Ho$ {H$gr R>mog H$m±M Ho$ Jmobo _|
Jmobo Ho$ Ho$ÝÐ C go 3·0 cm Xÿar na H$moB© N>moQ>m dm`w H$m ~wb~wbm \$§gm hþAm
h¡ & Jmobo Ho$ nXmW© H$m AndV©Zm§H$ 1·5 h¡ & dm`w _| {H$gr ~mhar {~ÝXþ E go
Jmobo H$s gVh _| go XoIZo na Bg ~wb~wbo H$s Am^mgr pñW{V kmV
H$s{OE & 5

55/1/1 Page 22 of 27

(ii) In Y -slit experiment, the two slits are separated
by a distance equal to 100 times the wavelength of light that
passes through the slits. Calculate :

(1) the angular separation in radians between the central
maximum and the adjacent maximum.

(2) the distance between these two maxima on a screen
50 cm from the slits. 5

OR

(b) (i) A spherical surface of radius of curvature R separates two
media of refractive indices n1 and n2. A point object is placed
in front of the surface at distance u in medium of refractive
index n1 and its image is formed by the surface at distance v,
in the medium of refractive index n2. Derive a relation
between u and v.

(ii) A solid glass sphere of radius 6 0 cm has a small air bubble
trapped at a distance 3 0 cm from its centre C as shown in the
figure. The refractive index of the material of the sphere is
1 5. Find the apparent position of this bubble when seen
through the surface of the sphere from an outside point E in
air. 5

55/1/1 Page 23 of 27 P.T.O.

IÊS> L>

34. {ZåZ{b{IV {MÌ EH$ {dÚwV n[anW AmaoI H$mo Xem©Vm h¡ & h_ {H$aImo\$ {Z`_m| H$m Cn`moJ
H$aHo$ {d{^Þ à{VamoYH$m| _| Ymam Am¡a CZHo$ {gam| na {d^dmÝVa kmV H$a gH$Vo h¢ &

Cn`w©º$ Ho$ AmYma na {ZåZ{b{IV àíZm| Ho$ CÎma Xr{OE :

(H$) Bg n[anW _| H$m¡Z-go {~ÝXþ g_mZ {d^d na h¢ ? 1

(I) ^wOm bg _| Ymam {H$VZr h¡ ? 1

(J) à{VamoY R3 Ho$ {gam| na {H$VZm {d^dmÝVa h¡ ? 2

AWdm

(J) à{VamoY R2 _| e{º$ j` {H$VZm h¡ ? $ 2

55/1/1 Page 24 of 27

SECTION E

34. The following figure shows a circuit diagram. We can find the currents

through and potential differences across different resistors using

Kirchhoff

Answer the following questions based on the above :

(a) Which points are at the same potential in the circuit ? 1

(b) What is the current through arm bg ? 1

(c) Find the potential difference across resistance R3. 2

OR

(c) What is the power dissipated in resistance R2 ? 2

55/1/1 Page 25 of 27 P.T.O.

35. ñQ´>m°pÝe`_
I{ZO h¡ & BgH$m
AndV©Zm§H$ Am¡a H«$m§{VH$ H$moU H«$_e: 2·41 Am¡a 24·5 h¢ Omo {H$ hrao Ho$ AndV©Zm§H$ Am¡a
H«$m§{VH$ H$moU Ho$ bJ^J ~am~a h¢ & Bg_| hrao Ho$ g^r JwU hmoVo h¢ & `hm± VH$ {H$ H$moB©
àdrU Om¡har ^r hrao Am¡a ñQ´>m°pÝe`_ Q>mBQ>¡ZoQ> Ho$ ~rM {d^oXZ Zht H$a nmVm h¡ & ñQ´>m°pÝe`_
Q>mBQ>¡ZoQ> go ~Zo {H$gr g_~mhþ {Ì^wOmH$a {àµÁ_ ABC Ho$ EH$ \$bH$ na H$moB© àH$me {H$aU
A{^bå~dV AmnVZ H$a ahr h¡ &

Cn`w©º$ Ho$ AmYma na {ZåZ{b{IV àíZm| Ho$ CÎma Xr{OE :
(H$) Bg àH$me {H$aU H$m Bg {àµÁ_ go JwOaVo hþE nW Amao{IV H$s{OE & 1

(I) {àµÁ_ _| àH$me H$m doJ kmV H$s{OE & 1

(J) nyU© AmÝV[aH$ namdV©Z Ho$ Xmo AZwà`moJm| H$s g§jon _| ì`m»`m H$s{OE & 2

AWdm
(J) àH$me Ho$ nyU© AmÝV[aH$ namdV©Z H$s n[a^mfm {b{IE & BgHo$ hmoZo Ho$ {bE Xmo eV]
~VmBE & 2

55/1/1 Page 26 of 27

35. Strontium titanate is a rare oxide a natural mineral found in Siberia.
It is used as a substitute for diamond because its refractive index and
critical angle are 2 41 and 24 5 , respectively, which are approximately
equal to the refractive index and critical angle of diamond. It has all the
properties of diamond. Even an expert jeweller is unable to differentiate
between diamond and strontium titanate. A ray of light is incident
normally on one face of an equilateral triangular prism ABC made of
strontium titanate.

Answer the following questions based on the above :

(a) Trace the path of the ray showing its passage through the prism. 1

(b) Find the velocity of light through the prism. 1

(c) Briefly explain two applications of total internal reflection. 2

OR

(c) Define total internal reflection of light. Give two conditions for it. 2

55/1/1 Page 27 of 27 P.T.O.

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