HBSE Class 12 Sample Paper 2023 Physics Set A

PRACTICE PAPER (2022-23)

CLASS: 12th (SR. SECONDARY) CODE -A
Roll No.

HkkSfrd foKku
PHYSICS
(Hindi and English Medium)
ACADEMIC/OPEN

(Time Allowed: 3 Hours) (Maximum Mark: 70)
 ¡
Please make sure that the printed pages in this question paper are 9 in number and
it contains 20 questions.

The Code No. on the right side of the question paper should be written by the
candidate on the front page of the answer book.

Before beginning to answer a question its Serial Number must be written.

Don’t leave blank page/pages in your answer book.


Execpt answer book, no extra sheet will be given. Write to the point and do not
strike the written answer.

Candidate must write their Roll Number on the question paper.


Before answering the questions, ensure that you have supplied the correct and
complete question paper, no claim in this regard, will be entertained after
examination.

General Instructions:-
(i) There are 20 questions in all.
(ii) All questions are compulsory.

1

(iii) Question No. 1 consists of fifteen (i-xv) objective type questions each of 1
mark.
(iv) Questions No 2 to 09 are very short answer type questions and carry 2 marks
each.
(v) Questions No 10 to 17 are short answer type questions and carry 3 marks each.
(vi) Question No 18 to 20 are long answer type questions and carry 5 marks each.
(vii) There is no overall choice. However an internal choice has been provided in all
three questions of 5 marks each. You have to attempt only one of the given
choices in such questions.
(viii) Use of calculator is not permitted.

lkekU; funsZ’k%&
(i) dqy 20 iz”u gSA
(ii) lHkh iz”u vfuok;Z gSA
(iii) igys iz”u esa (i-xv) 15 oLrqfu’B iz”u gS izR;sd 1 vad dk gSA
(iv) iz”u la[;k 2 ls 09 vfr y?kq vÙjkRed iz”u gS izR;sd 2 vad dk gSA
(v) iz”u la[;k 10 ls 17 y?kq vÙjkRed iz”u gSA izR;sd 3 vad dk gSA
(vi) iz”u la[;k 18 ls 20 nhFkZ vÙjkRed Ikz”u gSA izR;sd 5 vad dk gSA
(vii) iz”u i= esa dksbZ fodYi ugha gSA ;|fi 5 vad ds lHkh iz”uksa esa vkarfjd fodYi fn, x, gSA bu lc
iz”uksa esa vkidks ,d fodYi pquuk gSA
(viii) vad x.kd dk iz;ksx oftZr gSA

SECTION-A
¼[k.M&v½

1 (i) Angle between equipotential surface and electric field line is 1x15=15
(a) Zero (b) 180 (c) 90 (d) 45

lefoHko i`’B vkSj fo|qr {ks= js[kk esa dks.k gksrk gS%&
(a) Zero (b) 180 (c) 90 (d) 45

(ii) The unit of permittivity of free space E0 is :-
(a) C2 N-1 M-2 (b) N M2 C-2 (c) C N-2 M-1 (d) C2 N-2 M-2

fuokZr ijkoS|qrkad (Eo) dh bdkbZ gS%&
(a) C2 N-1 M-2 (b) N M2 C-2 (c) C N-2 M-1 (d) C2 N-2 M-2

2

(iii) What is the magnitude of force experienced by a stationary charge when placed in a
uniform mag, field ?

(a) F = qvB SInQ (b) F= qvB (c) F=Zero (d) None of these

,d foJke voLFkk ds vkos”k dks tc ,d leku pqacdh; {ks= esa j[kk tkrk gS rks ml ij yxus okys cy
dk ifjek.k D;k gS \

(a) F = qvB SInQ (b) F= qvB (c) F=Zero (d) buesa ls dksbZ ugha.

(iv) What is the number of electrons drifting past a section of a conductor if ‘a’ ampere
current is passed through it for b second?

;fn fdlh pkyd esa ‘a” ,Eih;j fo|qr /kkjk b le; ds fy, izokfgr gks jgha gS rks blesa ls xtjus okys
bySDVªkWuksa dh la[;k D;k gksxh \

(v) The nuclear model of atom was proposed by -----------------.

fdlds }kjk ijek.kq dk ukfHkdh; ekWMy izLrkfor fd;k x;k -----------------------------------

(vi) A Proton and an α particle with equal momenta enter normal to a uniform mag. Field.
Their ratio of radii is

(a) 2:1 (b) 1:2 (c)1:1 (d)1:4
izkVs kWu vkSj α - d.k ftudk laox
s cjkcj gS os ,d leku pqacdh; {ks= esa yacor izo”s k djrs gSA mudh f=T;k
dk vuqikr D;k gS%&

(a) 2:1 (b) 1:2 (c)1:1 (d)1:4

(vii) An electric lamp is rated at 110 W and 220 V supply. Find the current flowing
through the bulb.

,d fctyh cYc ftldh jsfVax 110 W vkSj 220 V gSA bl cYc esa izokfgr gksus okyh fo|qr /kkjk D;k gksxh \

(viii) Total internal reflection takes place when light travels from:-
(a) Water to glass (b) Glass to diamond (c) Water to air (d) Air to mercury.

iw.kZ vkarfjd ijkorZu laHko gksxk tc izdk”k tkrk gS%&

3

(a) ty ls dk¡p (b) dk¡p ls ghjk (c) ty ls ok;q (d) ok;q ls ikjk

(ix) Name the electromagnetic radiation used for viewing objects through haze and fog.

(ix) In the following nuclear reaction ;
11C 11B + B+ + X

What does X stand for ?
1
X1 ds LFkku ij D;k gksxk \
11C 11B + B+ + X

(xi) The de-Broglie wavelength associated with a particle of momentum P is given by __
,d d.k ftldk laosx P gS mlls tqMh Mh cjkWxfy rajxnS/;Z dk 0;atd fn;k tkrk gS&&&&&&&&&&&&

(xii) If the intensity of the incident radiation in a photo cell is increased, how does the
stopping potential vary?

(xiii) Given total energy of electron in first excited state of hydrogen atom = ev,
what are the values of K.E and P.E in this state?

= ev

(xiv) Net charge on a P- type semi conductor is ------------
P

(xv) Two thin lenses of power +6D and -2D are in contact, what is the focal length of
combination.

nks ysl
a ftudh {kerk +6D vkSj -2D gSA ;s ,d nwljs ds laidZ esa gSA bl la;kstu dh Qksdl nwjh D;k gksxh\

4

(SECTION-B)

Q-2. Two coherent sources, whose intensity ratio is 16:1 produce interference fringes.
Calculate the ratio of intensity of maxima and minima in the fringe system. 2

16:1

Q-3. Define the coefficient of mutual induction. Give its units mention two factors on
which mutual inductance between a pair of coil depends. 2

Q-4. Draw the sketch of variation of resistivity with temperature in the following:- 2
(i) Conductor (ii) Semiconductor

fuEu ds fy, izfrjks/kdrk vkSj rkieku ds e/; xzkQ cuk,%&

(i) pkyd (ii) v/kZpkyd

Q-5. An electric field exerts a torque on an electric dipole placed in its. When is the
torque – (i) Zero (ii) maximum 2

,d fo|qr {ks= ,d oS|qr f}/kzqo ij cyk/kw.kZ yxkrk gSA ;g oS|qr f}/kzqo fo|qr {ks= esa j[kk gSA dc ;g cyk/kw.kZ
(Torque) (i) “kwU; gksxk (ii) vf/kdrr gksxkA

Q-6. The susceptibility of a magnetic material is 2
(i) &4-2x10-6 (ii) 1.9x10-5

What types of material do they represent ?

(i) &4-2x10-6 (ii) 1.9x10-5

Q-7 Write the truth table for the given circuit. 2
5

fuEufyf[kr ifjiFk ds fy,
lR; lkj.kh cukb,A

Q-8 Write the relation between kinetic energy of α particle and its distance of closest
approach from nucleus in Rutherford α- seattering experiment. 2

jnjdksMZ ds α d.kksa ds izdh.kZu iz;ksx esa α d.kksa dh xfrt ÅtkZ vkSj fudVre n`f’Vdks.k dh nwjh ds chp
lac/a k fy[ksA

Q.9 List the factors on which the capacitance of a parallel plate capacitor depend. 2

lekarj IysV la/kkfj= dh /kfjrk fdu dkjdksa ij fuHkZj djrh gSA mudh lwph cuk,A

SECTION-C

Q.10 State Gauss’s law in electrostatics, Use it to determine electric field due to
infinitely long straight wire which is uniformly charged. 3

fLFkj oS|qfrdh esa xkWl dk fu;e crkb,A ,d rkj tks leku :Ik ls vkosf”kr gS mldk fo|qr {ks= fudkfy,
¼xkWl ds fu;e dk iz;ksx djds½

Q-11 Explain the working principle of ac generator with the help of a labelled diagram. 3

ac tfu= ds dke djus ds fl)kar dh ukekafdr fp= }kjk O;k[;k djsaA

Q-12 Explain the principle of potentiometer, Draw a labeled circuit diagram to
determine internal resistance of the cell. 3
6

foHkoekih ds dke djus ds fl)kar dh O;k[;k dhft,A foHkoekih ds iz;ksx }kjk fdlh lsy dk vkarfjd
izfrjks/k dSls fudkyrs gS \ ukekafdr fo|qr ifjiFk cuk,A

Q-13 AC is supplied to a series LCR circuit, Draw the relevant phasor diagram. Obtain
the resonance condition. 3

(ii) A series LCR circuit with R= 44Ω, C= 8 µF and L= 50H is connected to a
variable freq. 220 V ac supply. Calculate angular frequency at resonance
condition.
(i) Js.khc) LCR ifjiFk dks izO;korhZ /kkjk dh vkiwfrZ dh xbZ gSA blls lacaf/kr Qstj vkjs[k cuk,A
vuqukn fLFkfr dks izkIr dhft,A
(ii) Js.khc) LCR ifjiFk esa R=44Ω, C=8 µF vkSj L= 50H, bl ifjiFk dks ifjorZu”khy vko`fÙk
okyh izO;korhZ /kkjk dh vkiwfrZ dh xbZ gSA vuqukn dh fLFkfr esa dks.kh; vko`fÙk fudkfy,A

Q-14 A radio can tune into any station in the 7.5 MHz ls 21 MHz. What is the
corresponding wavelength band? 3

,d jsfM;kslsV 7.5 MHz ls 21 MHz. vko`fÙk ds LVs”ku ij V;wu djrk gSA blds vuq:Ik rajxnS/;Z
fudkfy,A

Q-15 Plot the graphs showing the variation of photo electric current with anode
potential in the following cases:- 3

(i) Two light beams of same wavelength but different intensity.
(ii) Two light beams of different frequencies but same intensity.

fuEufyf[kr fLFkfr;ksa esa izdk”k fo|qr/kkjk vkSj ,suksM foHko ds chp vkjs[k [khfp,%&

(i) nks fofdj.k ftudh rjaxnS/;Z ,d leku gks ijarq rhozrk vyx gksA
(ii) nks fofdj.k ftudh vko`fÙk vyx&vyx gks ijarq rhozrk ,d tSlh gksA

Q-16 Sate the laws of radioactive decay. Define the term decay constant for a radioactive
substance. How is related to half file? 3

jsfM;ks/kehZ {k; ds fu;e fyf[k,A ,d jsfM;ks/kehZ inkFkZ ds {k; fLFkjkad dh ifjHkk’kk nhft,A ;g
v/kZthou dky ls dSls lacaf/kr gS\

7

Q-17 (i) Show by ray diagrams how a totally reflecting prism of glass can be used to
deviate ray of light through 900 aand 180o 3

(iii) The refractive index of diamond is 2.42. Calculate the speed of fight in
diamond.

(i) fdj.k vkjs[k }kjk iznf”kZr dhft, fd fdl izdkj iw.kZ vkarfjd ijkorZu djus okyk fizTe izdk”k
dh fdj.kksa dks fopfyr djrk gS (a) 90o ds dks.k ls (b) 180o ds dks.k lsA

(ii) ghjs dk vioÙkZukad 2-42 gSA blesa izdk”k dk osx fudkfy,A

SECTION-D

Q-18 (i) Explain the principle and working of moving coil Galvanometer with the help
of diagram. 5

(ii) How can this be converted into ammeter and voltmeter?

(i) py dqaMyh /kkjkekih (Galvanometer) ds fl)kar vkSj dk;Zfof/k dh ukekafdr fp= }kjk O;k[;k dhft,A

(ii) bl xSYosuksehVj dks ,ehVj vkSj oksYVehVj es dSls ifjofrZr fd;k tk ldrk gS \

OR

Q-18 (i) Explain the principle and working of cyclotron with the help of diagram, Show
that time of revolution of ion is independent of its speed or radius of its orbit.

(ii) State the limitations of this device.

(i) lkbdyksVjksu ds fl)kar vkSj dk;Zfof/k dh ukekafdr fp= }kjk O;k[;k dhft,A vkosf”kr d.kksa dk ifjØe.k
le; d.kksa dh xfr vkSj muds iFk dh f=T;k ls Lora= gksrk gSA bl rF; dks iznf”kZr dhft,A

(ii) bl midj.k dh dfe;k¡ fyf[k,A

Q-19 (i) What is doping? How is it done to make p and n type semiconductors? 5

(ii) Draw the energy level diagram for p and n type semiconductor.

8

(i) Mksfiax D;k gS \ bldh enn ls P vkSj N izdkj ds v/kZ pkyd dSls cuk, tkrs gS \
(ii) P vkSj N izdkj ds v/kZpkyd ds fy, ÅtkZ Lrj vkjs[k cuk,A

OR

(i) Draw a circuit diagram to study characteristics of transistor (n p n) in common
emitter configuration.
(ii) Draw the sketch of (a) Input characteristics (b) Output characteristics for this
configuration.
(i) fdlh n p n VªkaftLVj ds CE foU;kl esa vfHkykf{k.kd ds v/;;u ds ifjiFk vkjs[k cukb,A
(ii) bl foU;kl ds (a) fuos”k vfHkykf{k.kd (ii) fuxZr vfHkykf{k.kd ds vkjs[k [khapsA

Q-20 (i) What do you mean by polarization? What types of waves can be polarized?
Explain polarization by refection and hence deduce Brewster’s law. 5

(ii) Calculate refractive index if angle of polarization is 60.

(i) izdk”k dk /kzqo.k fdls dgrs gS\ fdl izdkj dh rjaxksa dk /kzqo.k gksrk gS\ ijkorZu }kjk /kqzo.k dSls
gksrk gS vkSj blls cjsosLVj dk fu;e fu:fir dhft,A
(ii) viorZukad fudkfy, ;fn /kzqo.k dks.k 60- gSA

OR

Q-20 (i) What is hens maker formula? What assumptions are made for deriving this
formula? Derive lens maker formula using a convex lens.
(ii) The radius of curvature of each surface of a convex lens of refractive index 1.5
is 40 cm, calculate ate the power.

(i) ysal esdj dk fu;e D;k gS\ bl fu;e dks fudkyus ds fy, dkSu lh dYiuk,¡ dh xbZ gS\ bl
lw= dks mÙky ysal ds fy, fudkfy,A

(ii) ,d mÙky ysl
a ftldh izR;sd lrg dh oØrk f=T;k 40 cm gSA bl ysl
a dk vnorZukad 1-5 gSA
bl ysl
a dh {kerk fudkfy,A

9