Rajasthan Board 12th Physics Sample Paper 2021

mPp ek/;fed ijh{kk ekWMy iz'u&i=&2021
SENIOR SECONDARY EXAMINATION,MODEL QUESTION PAPER-2021

HkkSfrd foKku
PHYSICS
le;% 3¼ ?k.Vs iw.kkZd 56
ijh{kkfFkZ;ksa ds fy, lkekU; funZs'k %&
GENERAL INSTRUCTION TO THE EXAMINEES:
1- ijh{kkFkhZ loZizFke vius iz'u i= ij ukekad vfuok;Zr% fy[ksaA
Candidate must write first his/her Roll No. on the question paper
compulsorily.
2- lHkh iz'u djus vfuok;Z gSA
All the questions are compulasory.
3- lHkh iz'uksa dk mÙkj nh xbZ mÙkj iqfLrdk esa gh fy[ksaA
Write the answer to all questions in the given answer book only.
4- ftu iz'uksa esa vkUrfjd [k.M gS mu lHkh ds mÙkj ,d lkFk gh fy[ksaA
For questions having more than one part, the answers to those parts are to
be written together in continuity.
5- iz'u i= ds fgUnh o vaxzsth :ikUrj esa fdlh izdkj dh =qfV@ vUrj@fojks/kkHkkl gksus ij fgUnh
Hkk"kk ds iz'u dks lgh ekusAa
If there is any error/difference/contradiction in Hindi & English version of
the question paper, the question of the Hindi version should be treated valid.
6- iz'u dk mÙkj fy[kus ls iwoZ iz'u dk Øekad vo'; fy[ksaA
Write down the serial number of the question before attempting it.
7- iz'uksa dk vadHkkj fuEukuqlkj gSA
Weightage of marks for the question is as follows.
[k.M iz'u la[;k iz'uksa dh la[;k vad izR;sd iz'u dqy vad Hkkj
[k.M&v(A) 1 ( i to x ), 2 to 11 20 1 20
[k.M&c(B) 12 to 15 4 2 8
[k.M&l(C) 16 to 19 4 3 12
[k.M&n(D) 20 to 21 2 4 8
[k.M&;(E) 22 to 23 2 4 8

7- iz'u Øekad 16 ls 23 esa vkarfjd fodYi gSaA
There are internal choices in Question Nos. 16 to 23

[k.M ,
Section -A

1-(i)-(x) cgqfodYi iz'uksa ds lgh fodYi dk p;u dj mŸkj nh xbZ mRrj iqfLrdk esa fyf[k,A
Choose the Correct answer from multiple choice and write in given answer book.

¼i½ vkos'k dk ek=d gS
¼v½ dwykWe ¼c½ oksYV
¼l½ ,sfEi;j ¼n½ U;wVu
Unit of charge is 1
(A) Coulomb (B) Volt
(C) Ampere (D) Newton
¼ii½ fp= esa fn;s x;s dkcZu izfrjks/kd dk eku gSA izfrjks/kd dh nwljh oy; dk jax
gksxkA

yky \ gjk lqugjk
¼v½ ihyk ¼c½ dkyk
¼l½ lQsn ¼n½ yky
In given diagram, value of carbon resistor is . color of second ring of resistor will be
1

Red ? Green Golden

(A) Yellow (B) Black
(C) White (D) Red
¼iii½ loZizFke fo|qr rFkk pqEcdRo ds e/; lEca/k dks fdl oSKkfud us irk yxk;k\
¼v½ ykWjUs t ¼c½ vkWjLVsM
¼l½ U;wVu ¼n½ vkbUlVhu
First of all, which scientist find out the relation between electric and magnetism is? 1
(A) Lorentz (B) Orested
(C) Newton (D) Einstein
¼iv½ i`Foh ds pqEcdh; /kzqoksa ij ufr dks.k dk eku gksrk gSA
¼v½ 90° ¼c½ 60°
¼l½ 0° ¼n½ 180°
Value of dip angle at earth's magnetic pole is . 1
(A) 90° (B) 60°

(C) 0° (D) 180°

¼v½ vuquknh fLFkfr esa oksYVrk rFkk /kkjk esa dykUrj dk eku gksrk gSA
¼v½ 90° ¼c½ 0°

¼l½ 180° ¼n½ 45°
In resonance position, the phase angle between voltage and current is 1
(A) 90° (B) 0°

(C) 180° (D) 45°
¼vi½ ySal dh 'kfDr ¼P½ o Qksdl nwjh ¼f½ esa lEca/k gSa
¼v½ P=1/f ¼c½ P=1/2f
¼l½ P=f ¼n½ P=1/3f
Relation between power of lens (P) and focal length (f) is 1
(A) P=1/f (B) P=1/2f
(C) P=f (D) P=1/3f
¼vii½ vkbUlVhu dh izdk'k fo|qr lehdj.k gSA
¼v½ ¼c½

¼l½ ¼n½
Photo electric equation of Einstein is 1
(A) (B)

(C) (D)

¼viii½ nzO;eku la[;k esa o`f) gksus ij ukfHkd ls lacaf/kr dkSulh jkf'k ifjofrZr ugha gksrh gSA
¼v½ nzO;eku ¼c½ vk;ru
¼l½ ca/kuÅtkZ ¼n½ ?kuRo
On increasing the mass number which of the nuclear properties is not changed 1
(A) Mass (B) Volume
(C) Binding energy (D) Density
¼ix½ ije'kwU; rki ij uSt v)Zpkyd gksrs gSa
¼v½ vfrpkyd ¼c½ v/kZpkyd
¼l½ dqpkyd ¼n½ pkyd
At absolute zero temperature, intrinsic semiconductor is 1
(A) Superconductor (B) Semiconductor
(C) Insulator (D) Conductor

¼x½ fuEu esa ls dkSulh fofdj.k dh rjax nS/;Z U;wure gksrh gS
¼v½ X&fdj.ksa ¼c½ &fdj.ksa
¼l½ &fdj.ksa ¼n½ fdj.ksa

Which radiation has least wavelength 1
(A) X-rays (B) -rays
(C) -rays (D) -rays
fuEu iz'uksa ds mŸkj ,d iafDr esa ns %& ¼iz'u Øekad 02 ls 08 rd½
Give the answer of the following Question in one line (Q. No. 02 to 08)

2- fcUnq /kukos'k ds fy, fo|qr {ks= js[kk,a [khfp,A
Draw the electric field lines for positive point charge. 1

3. fdj[kkWQ dk f}rh; fu;e fyf[k,A
Write the Kirchhoff's second law. 1

4. ck;ks lkoVZ dk fu;e fyf[k,A
Write the Biot-Savart's law. 1

5 pqEcdRo ds fy, xkml dk fu;e fyf[k,A
Write the Gauss's law for magnetism. 1

6 izdk'k ds foorZu ls vki D;k le>rs gS\
What do you understand by diffraction of light? 1

7 nsgyh vko`fr dks ifjHkkf"kr dhft,A
Define the threshold frequency. 1

8 OR }kj dh lR;eku lkj.kh cukb,

Make truth table of OR gate. 1
funZs'k % iz'u la[;k 9 ls 11 ds mÙkj] mÙkjiqfLrdk esa nhft,A
Note : Write answers of questions no. 9 to 11 in answer book.

9 fo/kqr {ks= dh fn'kk lefoHko i`"B ds ry ds ------------------------------------ gksrh gSA
The direction of electric field is always ……………………………… on equipotential surface. 1
10 D;wjh fu;e ds vuqlkj vuqpqEcdh; inkFkksZ dh pqEcdh; izo`fŸk ije rki ds -------------------------- gksrh gSA
According to curie's law, magnetic susceptibility of paramagnetic material is……………………….. to
absolute temperature. 1
11 fo|qr pqEcdh; rjaxksa ds lapj.k esa fo|qr {ks= ,oa pqEcdh; {ks= ,d nwljs ds -----------------------------gksrs gS
In propagation of electromagnetic waves, electric field and magnetic field are ……………………….. to
each other. 1

[k.M& c

Section - B
12 ,d izR;korhZ /kkjk ifjiFk esa oksYVrk V=50 Sin(314t + ) oksYV gS rks Kkr djs
(i) Vrms
(ii) izR;korhZ oksYVrk dh vko`fr
The voltege in an ac circuit is V=50 Sin(314t + Ø) volt then find out.
(i) Vrms
(ii) Frequency of ac voltage
1+1=2
13 10000 V ds foHkokUrj ls Rofjr bysDVªku ls lac) nzO; rjaxnS/;Z Kkr dhft,A
Find out the wavelength of an electron accelerated by a potential difference of 10000 V. 2

14 ukfHkdh; HkV~Vh dk ukekafdr fp= cukb,A
Draw labelled diagram of Nuclear reactor. 2

15 ,d vk;ke ekMqfyr rjax esa vf/kdre vk;ke 10V rFkk U;wure vk;ke 2V gS rks ekWMqyu lwpdkad
Kkr djsA
The maximum and minimum amplitude for an amplitude modulated wave are 10V and 2V respectively.
Calculate the modulation index. 2

[k.M& l
Section -C
16 foHkoekih dh lgk;rk ls nks izkFkfed lSyksa ds fo|qr okgd cyks dh rqyuk dk O;atd izkIr dhft,A
vko';d ifjiFk fp= cukb,A
foHkoekih dh lgk;rk ls fdlh izkFkfed lsy dk vkUrfjd izfrjks/k Kkr djus dk O;atd izkIr
dhft;sA vko';d ifjiFk fp= cukb,A
Derive a expression for obtaining comparison of emf of two primary cell's with the help of
potentiometer. Draw necessary circuit diagram. 2+1=3
or
Derive expression for obtaining internal resistance of a primary cell with the help of potentiometer.
Draw necessary circuit diagram. 2+1=3

17 fuyfEcr dq.Myh /kkjkekih fdls dgrs gSa \ bldk ukekafdr fp= cukb,A fl) dhft, fd /kkjkekih
dh dq.Myh esa izokfgr /kkjk dq.Myh esa mRiUu fo{ksi ds vuqØekuqikrh gksrh gSA
gSYe gksYVt dq.Mfy;ka fdls dgrs gS\ vko';d fp= cukb,A fl) dhft;s fd gSYe gksYVt dq.Myh
esa izkIr ,d leku pqEcdh; {ks= dk eku izR;sd dq.Myh }kjk blds dsUnz ij mRiUu pqEcdh; {ks= dk
1-432 xquk gksrk gSA
What is suspended coil galvanometer? Draw labelled diagram of it. Prove that current flowing in the coil
of galvanometer is directly proportional to the deflection in the coil. 1+1+1=3

or
What is Helmholtz coil ? Draw necessary diagram. Also prove that the value of a uniform magnetic field
obtained in the Helmholtz coil is 1.432 times the magnetic field generated by each coil at its centre.
1+1+1=3
18 ,d gh vko`fÙk dh nks rjaxksa ds vk;ke 2%1 vuqikr esa gSA O;frdj.k {ks= esa dEiuksa ds egÙke o U;wure
vk;keksa rFkk rhozrkvksa dk vuqikr Kkr dhft,A
fdlh O;frdj.k iz;ksx esa I rFkk 4I rhozrkvksa ds nks L=ksrksa dk mi;ksx fd;k x;k gSA mu fcUnqvksa ij
rhozrk Kkr dhft,] tgk¡ ij v/;kjksi.k djrh gqbZ nksuks rjaxks ds e/; dykUrj gS &
¼v½ 'kwU; ¼c½

For two waves of same frequency the ratio of amplitude is 2:1. Find out maximum and minimum ratio of
amplitude and intensities of vibrations within interfering region. $ =3

or
In an experiment for interference two sources of intensities I and 4I are used. Find out the intensities at
those point where the phase difference between the waves from two sources interfering each other is

(A) Zero (B) $ =3

19 gkbZMªkt
s u ijek.kq dh ckej Js.kh dh nwljh js[kk ds fy, rjaxnS/;Z dk eku 4861 A° gS rks bl Js.kh dh
pkSFkh js[kk ds rjaxnS/;Z dh x.kuk djksA
;fn gkbZMªkt
s u ijek.kq ds LisDVªe esa ykbeu Js.kh dh izFke js[kk dh rjaxnS/;Z 1215 A° gS rks ckej
Js.kh dh f}rh; js[kk dh rjaxnS/;Z Kkr dhft,A

For hydrogen atom the wave length for second line in Balmer series is 4861 A°. Find out the wave length
of 4th line in this series. 3
or

If in the spectrum of hydrogen atom the wave length of first line in Lyman series is 1215A°. Find out the
wave length of second line of Balmer series. 3

[k.M&n
Section -D
20 mHk;fu"B vk/kkj foU;kl esa la;ksftr fdlh NPN VªkaftLVj ds vfHkyk{kf.kd oØ izkIr djus ds fy,
izk;ksfxd O;oLFkk dk ifjiFk fp= cukb,A fuos’kh vfHkyk{kf.kd oØ cukdj bldh O;k[;k dhft,A
P-N laf/k Mk;ksM ds vxz rFkk i’p vfHkufr vfHkyk{kf.kd oØ izkIr djus gsrq vko’;d izk;ksfxd
O;oLFkk dk ifjiFk fp= cukb,A vfHkyk{kf.kd oØ cukdj bldh O;k[;k dhft,A
Draw the circuit diagram of practical arrangement for obtain characteristic curve for a NPN transistor in
common base configuration. Draw and explain its input characteristic curve.
or
Draw the circuit diagram of practical arrangement for obtain characteristic curve for forward and reverse
biased P-N junction diode. Draw and explain its characteristic curve.

21 le:i pqEcdh; {ks= esa ?kw.kZu djrh /kkrq dh NM+ esa izsfjr fo|qr okgd cy dk O;atd fyf[k,A
vko’;d fp= cukb,A
,d L-R ifjiFk dks izR;korhZ L=ksr ls tksM+k x;k gSA Qstj vkjs[k dh lgk;rk ls
izfrck/kk dk O;atd fyf[k,A vko’;d Qstj vkjs[k cukb,

Write an expression for induced emf in a conductor rod rotating in a uniform magnetic field. Draw
necessary diagram.
or
A L-R circuit is connected to an AC source Write an expression for impedance using
phasor diagram. Draw necessary phasor diagram.

[k.M bZ
Section -E
22 fo|qr f}/kqo dks ifjHkkf"kr dhft,A
fo|qr f}/kqo ds dkj.k mlds v{kh; js[kk ij fLFkr fdlh fcUnq ij ifj.kkeh fo|qr {ks= dh rhozrk dk
O;atd izkIr dhft,A
vko';d fp= cukb;sA
fLFkj fo|qfrdh ds fy, xkWml dk fu;e fyf[k;sA
le:i vkosf'kr vifjfer pkyd ifV~Vdk ds dkj.k fo|qr {ks= dh rhozrk dk O;atd O;qRiUu dhft,A
vko';d fp= cukb;sA
la/kkfj= fdls dgrs gSA
lekUrj iV~V la/kkfj= dh /kkfjrk dk O;atd O;qRiUu dhft,A
vko';d fp= cukb;sA

Define electric dipole.
Derive an expression for intensity of electric field at an axial point of an electric dipole.
Draw necessary diagram.
or
Write gauss's law in electrostatics.
Derive an expression for electric field intensity due to an infinite uniformly charged infinite conducting
plate.
Draw necessary diagram.
or
What is a capacitor ?
Derive an expression of capacitance of the parallel plate capacitor.
Draw necessary diagram.

23 vko/kZu {kerk dks ifjHkkf"kr dhft,A
ysl
a esdj lw= O;qRiUu dhft,A

vko';d fp= cukb,A

izdk'k rjaxksa ds O;frdj.k dks ifjHkkf"kr dhft,A
O;frdj.k fÝat izfr:i mRiUu djusa ds fy, ;ax f}fLyV iz;ksx dk fp= cukb,A
iznhIr fÝatksa ds fy, fÝat pkSM+kbZ ds O;atd dh O;qRifÙk dhft,A
izdk'k ds fo{ksi.k dks ifjHkkf"kr dhft,A
,do.khZ izdk'k fdj.k ds dk¡p ds fizTe ls xqtjus ij viorZu dks n'kkZus okyk fdj.k fp= cukb,A
fizTe dks.k rFkk U;wure fopyu dks.k ds inksa esa dk¡p ds viorZukad dk O;atd Kkr dhft,
Define magnifying power.

Derive lens maker formula

Draw necessary diagram.
or
Define interference of light waves.
Draw a diagram of young's double slit experiment to produce interference fringe pattern.
Derive an expression of fringe width for bright fringes.
or
Define dispersion of light.
Draw a ray diagram for a monochromatic ray refracting from a glass prism.
Derive the expression for refractive index of glass in terms of prism angle and angle of minimum
deviation.