CBSE Class 10 Science Question Paper 2020 Set 31-4-2

H$moS> Z§.
Code No. 31/4/2
amob Z§. narjmWu H$moS >H$mo CÎma-nwpñVH$m Ho$ _wI-n¥ð
Roll No. >na Adí` {bIo§ &
Candidates must write the Code on the
title page of the answer-book.

ZmoQ> NOTE
(I) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _o§ _w{ÐV (I) Please check that this question
n¥ð> 23 h¢ & paper contains 23 printed pages.

(II) àíZ-nÌ _| Xm{hZo hmW H$s Amoa {XE JE H$moS (II) Code number given on the right
>Zå~a H$mo N>mÌ CÎma-nwpñVH$m Ho$ _wI-n¥ð> na hand side of the question paper
{bI| & 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 _| (III) Please check that this question
>30 àíZ h¢ & paper contains 30 questions.
(IV) H¥$n`m àíZ H$m CÎma {bIZm ewê$ H$aZo go (IV) Please write down the serial number
nhbo, CÎma-nwpñVH$m _| àíZ H$m H«$_m§H$ of the question in the answer-book
Adí` {bI| & before attempting it.
(V) Bg àíZ-nÌ H$mo n‹T>Zo Ho$ {bE 15 {_ZQ >H$m (V) 15 minute time has been allotted to
g_` {X`m J`m h¡ & àíZ-nÌ H$m {dVaU read this question paper. The
nydm©• _| 10.15 ~Oo {H$`m OmEJm & question paper will be distributed
10.15 ~Oo go 10.30 ~Oo VH$ N>mÌ Ho$db at 10.15 a.m. From 10.15 a.m. to
10.30 a.m., the students will read the
àíZ-nÌ H$mo n‹T>|Jo Am¡a Bg Ad{Y Ho$ Xm¡amZ question paper only and will not
do CÎma-nwpñVH$m na H$moB© CÎma Zht {bI|Jo & write any answer on the
answer-book during this period.

{dkmZ
SCIENCE

{ZYm©[aV g_` : 3 KÊQ>o A{YH$V_ A§H$ : 80
Time allowed : 3 hours Maximum Marks : 80

.31/4/2 1 P.T.O.

gm_mÝ` {ZX}e :
{ZåZ{b{IV {ZX}em| H$mo ~hþV gmdYmZr go n{‹T>E Am¡a CZH$m g™Vr go nmbZ H$s{OE :
(i) `h àíZ-nÌ VrZ IÊS>m| _§o {d^m{OV {H$`m J¶m h¡ — H$, I Am¡a J & Bg àíZ-nÌ _| àíZm|
H$s g§»`m 30 h¡ & g^r àíZ A{Zdm`© h¢ &
(ii) IÊS> H$ Ho$ g^r àíZ/CZHo$ ^mJ, àíZ g§»`m 1 go 14 VH$ EH$-EH$ A§H$ Ho$ h¢ & BZ àíZm|
_| ~hþ{dH$ënr àíZ, A{V bKw-CÎmar` àíZ VWm A{^H$WZ-H$maU àH$ma Ho$ àíZm| H$mo
gpå_{bV {H$`m J`m h¡ & BZ àíZm| Ho$ CÎma EH$ eãX AWdm EH$ dmŠ` _| {XE OmZo Mm{hE &
(iii) IÊS> I _| àíZ g§»`m 15 go 24 VH$ bKw-CÎmar` àH$ma Ho$ àíZ h¢, àË`oH$ àíZ 3 A§H$
H$m h¡ & BZ àíZm| H$m CÎma 50 go 60 eãXm| go A{YH$ Zht hmoZm Mm{hE &
(iv) IÊS> J _| àíZ g§»`m 25 go 30 VH$ XrK©-CÎmar` àH$ma Ho$ àíZ h¢, àË`oH$ àíZ 5 A§H$
H$m h¡ & BZ àíZm| H$m CÎma 80 go 90 eãXm| go A{YH$ Zht hmoZm Mm{hE &
(v) CÎma g§{já VWm q~Xþdma hmoZo Mm{hE Am¡a gmW hr Cn`w©º$ eãX gr_m H$m `Wmg§^d nmbZ
{H$`m OmZm Mm{hE &
(vi) àíZ-nÌ _| g_J« na H$moB© {dH$ën Zht h¡ & VWm{n àË`oH$ IÊS> _| Hw$N> àíZm| _| Am§V[aH$
{dH$ën {XE JE h¢ & Eogo àíZm| _§o go Ho$db EH$ hr {dH$ën H$m CÎma {b{IE &
(vii) BgHo$ A{V[aº$, Amdí`H$VmZwgma, àË`oH$ IÊS> Am¡a àíZ Ho$ gmW `Wmo{MV {ZX}e {XE JE h¢ &

IÊS> H$
1. ñdñW ahZo Ho$ {bE h_| ^moOZ nH$mZo Ho$ {bE {H$Z Vobm| H$m Cn`moJ H$aZm Mm{hE ? 1

2. ào[aV {dÚwV² Ymam H$s n[a^mfm {b{IE & 1

3. {ZåZ{b{IV AZwÀN>oX Am¡a n‹T>r J`t g§~§{YV g§H$ënZmAm| H$s ì`m»`m Ho$ AmYma na àíZ
g§»`m 3(a) go 3(d) Ho$ CÎma Xr{OE :
gZ² 1800 Ho$ bJ^J VH$ Ho$db 30 VÎd hr kmV Wo & 1817 _| S>m°~oamBZa Am¡a
1866 _| Ý`yb¢S²>g Zo V~ VH$ kmV VÎdm| H$mo ì`dpñWV H$aZo Ho$ {bE à`mg {H$E Am¡a Hw$N>
{Z`_ ~ZmE {OÝh| d¡km{ZH$m| Zo AñdrH$ma H$a {X`m & CZ àñVm{dV {Z`_m| Ho$ AñdrH$ma
{H$E OmZo Ho$ níMmV² ^r H$B© d¡km{ZH$m| Zo Eogo à{Vê$nm| H$s ImoO Omar aIr {Oggo VÎdm| Ho$
JwUY_m] H$m CZHo$ na_mUw Ðì`_mZm| Ho$ gmW g§~§Y ñWm{nV hmo gHo$ &
.31/4/2 2

General Instructions :
Read the following instructions very carefully and strictly follow them.
(i) This question paper comprises three Sections — A, B and C. There are
30 questions in the question paper. All questions are compulsory.
(ii) Section A – Questions no. 1 to 14 — all questions or part thereof are of
one mark each. These questions comprise Multiple Choice Questions
(MCQ), Very Short Answer (VSA) and Assertion–Reason type questions.
Answer to these questions should be given in one word or one sentence.
(iii) Section B – Questions no. 15 to 24 are short answer type questions,
carrying 3 marks each. Answer to these questions should not exceed 50 to
60 words.
(iv) Section C – Questions no. 25 to 30 are long answer type questions,
carrying 5 marks each. Answer to these questions should not exceed 80 to
90 words.
(v) Answers should be brief and to the point. Also the above mentioned word
limit be adhered to as far as possible.
(vi) There is no overall choice in the question paper. However, an internal
choice has been provided in some questions in each section. Only one of
the choices in such questions have to be attempted.
(vii) In addition to this, separate instructions are given with each section and
question, wherever necessary.

SECTION A

1. Which oils should be chosen for cooking to remain healthy ? 1

2. Define the term induced electric current. 1

3. Answer question numbers 3(a)  3(d) on the basis of your understanding
of the following paragraph and the related studied concepts :

Around the year 1800, only 30 elements were known. Dobereiner
in 1817 and Newlands in 1866 tried to arrange the then known elements
and framed laws which were rejected by the scientists. Even after the
rejection of the proposed laws, many scientists continued to search for a
pattern that correlated the properties of elements with their atomic
masses.
.31/4/2 3 P.T.O.

VÎdm| Ho$ dJuH$aU H$m _w»` lo` _oÝS>obr\$ H$mo OmVm h¡, {OÝhm|Zo VÎdm| H$s AmdV©
gmaUr Ho$ àma§{^H$ {dH$mg _| gdm©{YH$ _hÎdnyU© `moJXmZ {X`m & CÝhm|Zo VÎdm| H$mo CZHo$ _yb
JwUY_©, na_mUw Ðì`_mZ VWm amgm`{ZH$ JwUY_m] _| g_mZVm Ho$ AmYma na ì`dpñWV
{H$`m & CZHo$ hmBS´>mBS>m| Am¡a Am°ŠgmBS>m| Ho$ gyÌm| H$mo VÎdm| Ho$ dJuH$aU H$m _yb _mnXÊS>
_mZm J`m &
naÝVw _oÝS>obr\$ Ho$ dJuH$aU _| ^r Hw$N> H${_`m± Wt, Š`m|{H$ Bg_| g_ñWm{ZH$m| H$mo
H$moB© ñWmZ Zht {X`m J`m Wm & CÝhm|Zo AmdV© gmaUr _| Hw$N> [aº$ ñWmZ ^r N>mo‹S> {XE Wo &

3(a) _oÝS>obr\$ H$m AmdV© {Z`_ {b{IE & 1

3(b) _oÝS>obr\$ Zo AmdV© gmaUr _| Hw$N [aº$ ñWmZ Š`m| N>mo‹S> {XE Wo ? 1

3(c) `{X {H$gr g_yh _| {H$gr VÎd H$mo ‘R’ Aja go {Zê${nV {H$`m OmVm h¡, Vmo H$m~©Z
Ho$ hmBS´>mBS> Am¡a Am°ŠgmBS> H$mo H«$_e: {H$g àH$ma {Zê${nV {H$`m OmEJm ? 1

(i) RH4, RO

(ii) RH4, RO2

(iii) RH2, RO2

(iv) RH2, RO

3(d) g_ñWm{ZH$ 1

(i) {H$gr VÎd Ho$ dh na_mUw h¢ {OZHo$ amgm`{ZH$ JwUY_© g_mZ naÝVw na_mUw
Ðì`_mZ {^Þ hmoVo h¢ &
(ii) {^Þ-{^Þ VÎdm| Ho$ dh na_mUw h¢ {OZHo$ amgm`{ZH$ JwUY_© g_mZ naÝVw
na_mUw Ðì`_mZ {^Þ hmoVo h¢ &
(iii) {H$gr VÎd Ho$ dh na_mUw h¢ {OZHo$ amgm`{ZH$ JwUY_© {^Þ naÝVw na_mUw
Ðì`_mZ g_mZ hmoVo h¢ &
(iv) {^Þ-{^Þ VÎdm| Ho$ dh na_mUw h¢ {OZHo$ amgm`{ZH$ JwUY_© {^Þ naÝVw
na_mUw Ðì`_mZ g_mZ hmoVo h¢ &
.31/4/2 4

The main credit for classifying elements goes to Mendeleev for his
most important contribution to the early development of a Periodic table
of elements wherein he arranged the elements on the basis of their
fundamental property, the atomic mass and also on the similarity of
chemical properties. The formulae of their hydrides and oxides were
treated as basic criteria for the classification of the elements.

However, Mendeleev’s classification also had some limitations as it
could not assign the position to isotopes. He also left some gaps in the
periodic table.

3(a) State Mendeleev’s Periodic Law. 1

3(b) Why did Mendeleev leave some gaps in the Periodic table ? 1

3(c) If the letter ‘R’ was used to represent any of the elements in the
group, then the hydride and oxide of carbon would respectively be
represented as 1
(i) RH4, RO

(ii) RH4, RO2

(iii) RH2, RO2

(iv) RH2, RO

3(d) Isotopes are 1

(i) Atoms of an element with similar chemical properties but
different atomic masses.

(ii) Atoms of different elements with similar chemical properties
but different atomic masses.

(iii) Atoms of an element with different chemical properties but
same atomic masses.

(iv) Atoms of different elements with different chemical
properties but same atomic masses.

.31/4/2 5 P.T.O.

4. {ZåZ{b{IV AZwÀN>oX Am¡a n‹T>r J`t g§~§{YV g§H$ënZmAm| H$s ì`m»`m Ho$ AmYma na àíZ
g§»`m 4(a) go 4(d) Ho$ CÎma Xr{OE :

^maV AmO g§gmYZm| Ho$ AË`{YH$ XmohZ, Ob Am¡a _¥Xm Ho$ g§XÿfU VWm H$Mao H$mo
g§gm{YV H$aZo H$s {d{Y`m| H$s H$_r H$s g_ñ`m H$m gm_Zm H$a ahm h¡ & A~ g_` Am J`m
h¡ {H$ g§gma ‘‘EH$b-Cn`moJ ßbmpñQ>H$’’ H$mo {dXm H$ho & BgHo$ n`m©daU-{hV¡fr {dH$ënm|,
An{eîQ> ßbmpñQ>H$ H$m à^mdr EH$ÌrH$aU Am¡a CgH$m {ZnQ>mam H$aZo H$s {d{Y`m± {dH${gV
H$aZo Ho$ {bE à`mg {H$E OmZo Mm{hE &

BÝXm¡a Zo _mÌ 3 df© _| O¡d-IZZ Am¡a O¡d-CnMm`© H$s à{H«$`mAm| Ûmam 15 bmI
_r{Q´>H$ Q>Z H$Mao H$mo g§gm{YV {H$`m h¡ & O¡d-CnMm`© _| {H$gr b¡ÊS>{\$b _| OrdmUwAm| H$mo
S>mbH$a H$Mao H$mo àmH¥${VH$ ê$n go ‘AnK{Q>V’ {H$`m OmVm h¡ VWm O¡d-IZZ _| Q´>mo_b
_erZm| Ûmam H$Mao H$mo N>mZH$a ‘_¥Xm’ H$mo H$Mao go n¥WH²$ {H$`m OmVm h¡ & Bg eha Zo bJ^J
10 H$amo‹S> én`o IM© H$aHo$ 15 bmI _r{Q´>H$ Q>Z H$Mao H$m {ZnQ>mam H$aZo _| g\$bVm nmB© &
Eogm hr EH$ g\$b à`moJ Ah_Xm~mX _| ^r {H$`m J`m &

4(a) AnZo {dÚmb` _| An{eîQ> ßbmpñQ>H$ H$mo EH$Ì H$aZo H$s Xmo à^mdr {d{Y`m| H$m
CëboI H$s{OE & 1

4(b) ‘‘EH$b-Cn`moJ ßbmpñQ>H$’’ Ho$ X¡{ZH$ OrdZ _| H$moB© Xmo Cn`moJ {b{IE & 1

4(c) `{X ßbmpñQ>H$ H$m Cn`moJ amoH$ {X`m OmE, Vmo BgHo$ ñWmZ na H$moB© n`m©daU-{hV¡fr
{dH$ën H¡$go àXmZ {H$`m Om gH$Vm h¡ ? 1

4(d) Š`m Amn Eogm gmoMVo h¢ {H$ b¡ÊS>{\$b ñWb _| OrdmUw Cgr àH$ma H$m`© H$a|Jo O¡gm
do à`moJembm _| H$aVo h¢ ? AnZo CÎma H$s nw{îQ> H$s{OE & 1

.31/4/2 6

4. Answer question numbers 4(a)  4(d) on the basis of your understanding
of the following paragraph and the related studied concepts :

India today is facing the problem of overuse of resources,

contamination of water and soil and lack of methods of processing the

waste. The time has come for the world to say goodbye to ‘‘single-use

plastics’’. Steps must be undertaken to develop environment-friendly

substitutes, effective plastic waste collection and methods of its disposal.

Indore treated 15 lakh metric tonnes of waste in just 3 years,

through biomining and bioremediation techniques. Bioremediation

involves introducing microbes into a landfill to naturally ‘break’ it down

and biomining involves using trommel machines to sift through the waste

to separate the ‘soil’ and the waste component. The city managed to chip

away 15 lakh metric tonnes of waste at a cost of around < 10 crore. A

similar experiment was successfully carried out in Ahmedabad also.

4(a) State two methods of effective plastic waste collection in your

school. 1

4(b) Name any two uses of ‘‘single-use plastic’’ in daily life. 1

4(c) If we discontinue the use of plastic, how can an

environment-friendly substitute be provided ? 1

4(d) Do you think microbes will work similarly in landfill sites as they

work in the laboratory ? Justify your answer. 1

.31/4/2 7 P.T.O.

5. {ZfoMZ dh à{H«$`m h¡ {Og_| 1

(A) Za `w½_H$ H$m _mXm `w½_H$ H$s Amoa ñWmZmÝVaU hmoVm h¡ &
(B) Za Am¡a _mXm `w½_H$ Ho$ Ho$ÝÐH$m| H$m g§b`Z hmoVm h¡ &
(C) Za Am¡a _mXm OZZm§Jm| H$m Amg§OZ ({MnH$md) hmoVm h¡ &
(D) {H$gr OZZm§J Ûmam `w½_H$ ~ZVo h¢ &

6. _mZdm| Ho$ CËgO©Z V§Ì Ho$ {H$g ^mJ _|, àmapå^H$ {Zñ`§X _| ah OmZo dmbo Hw$N> nXmWm], O¡go
½byH$moµO, Eo_rZmo Aåb, bdU Am¡a Ob, H$m M`{ZV nwZademofU hmoVm h¡ ? 1

(A) _yÌ_mJ©
(B) d¥ŠH$mUw
(C) _yÌdm{hZr
(D) _yÌme`
AWdm
ñ`yS>monmo{S>`m hmoVo h¢ 1

(A) EH$H$mo{eH$s` Ordm| _| CnpñWV aoeo O¡ogr N>moQ>r g§aMZmE± &
(B) Hw$N> EH$H$mo{eH$s` Ordm| _| {dH${gV Hy$Q>nmX &
(C) _wI go ~mha AmVr bå~r Z{bH$m O¡gr g§aMZmE± &
(D) Am§Ìm| H$s {^{Îm`m| go Ow‹S>o MyfH$ &

7. _mZd n[ag§MaU V§Ì Ho$ {df` _| {ZåZ{b{IV _| go H$m¡Z-gm H$WZ ghr h¡ ? 1

(A) é{Ya Ho$db Am°ŠgrOZ H$m dhZ H$aVm h¡ VWm H$m~©Z S>mBAm°ŠgmBS> H$m dhZ Zht
H$aVm &
(B) _mZd öX` _| nm±M H$moîR> hmoVo h¢ &
(C) dmëd é{Ya Ho$ níM àdmh na amoH$ H$mo gw{ZpíMV H$aVo h¢ &
(D) öX` _| Am°ŠgrOZ-~hþb Am¡a Am°ŠgrOZ-Ý`yZ XmoZm| é{Ya {_{lV hmoVo h¢ &
.31/4/2 8

5. Fertilisation is the process of 1

(A) transfer of male gamete to female gamete.

(B) fusion of nuclei of male and female gamete.

(C) adhesion of male and female reproductive organs.

(D) the formation of gametes by a reproductive organ.

6. In the excretory system of human beings, some substances in the initial
filtrate such as glucose, amino acids, salts and water are selectively
reabsorbed in 1

(A) Urethra

(B) Nephron

(C) Ureter

(D) Urinary bladder

OR

Pseudopodia are 1

(A) small hair-like structures present on unicellular organisms.

(B) false feet developed in some unicellular organisms.

(C) long, tube-like structures coming out of the mouth.

(D) suckers which are attached to the walls of the intestines.

7. Which one of the following statements is correct about the human
circulatory system ? 1

(A) Blood transports only oxygen and not carbon dioxide.

(B) Human heart has five chambers.

(C) Valves ensure that the blood does not flow backwards.

(D) Both oxygen-rich and oxygen-deficient blood gets mixed in the
heart.
.31/4/2 9 P.T.O.

8. {H$gr Zm{^H$s` [aEoŠQ>a _| Zm{^H$s` D$Om© CËnÞ H$aZo Ho$ ~mao _| {ZåZ{b{IV _| go H$m¡Z-gm
H$WZ gË` Zht h¡ ? 1

(A) Bg_| D$Om© Zm{^H$s` {dIÊS>Z H$s à{H«$`m Ûmam àmßV hmoVr h¡ &
(B) Bg_| `yao{Z`_ Ho$ Zm{^H$ na CÀM D$Om© dmbo Ý`yQ´>m°Zm| H$s ~_~mar H$s OmVr h¡ &
(C) Bg à{H«$`m _| ûm¥§Ibm A{^{H«$`m hmoVr h¡ &
(D) Bg à{H«$`m _| {Z`§{ÌV Xa na {demb _mÌm _| D$Om© _wº$ hmoVr h¡ &
AWdm
n¥Ïdr Ho$ n¥îR> na D$Om© H$m g~go ~‹S>m òmoV h¡ 1

(A) O¡d_mÌm (~m`mo_mg)
(B) gm¡a {d{H$aU
(C) Ádma-^mQ>m
(D) ndZ

9. `{X {H$gr ì`{º$ Ho$ nmg nm±M à{VamoYH$ h¢ {OZ_| àË`oH$ H$m à{VamoY 1  h¡, Vmo dh BÝh|
5
g§`mo{OV H$aHo$ {H$VZm A{YH$V_ à{VamoY àmßV H$a gH$Vm h¡ ? 1
(A) 1
(B) 5
(C) 10 
(D) 25 
AWdm
{H$gr à{VamoYH$ H$m à{VamoY CgHo$ àmapå^H$ _mZ H$m AmYm H$a {X`m J`m h¡ & Eogm H$aZo
_|, `{X n[anW Ho$ AÝ` àmMbm| H$mo n[ad{V©V Z {H$`m OmE, Vmo Bg à{VamoYH$ _| VmnZ
à^md hmo OmEJm 1
(A) XþJwZm
(B) AmYm
(C) EH$-Mm¡WmB©
(D) Mma JwZm
.31/4/2 10

8. Which one of the following statements is not true about nuclear energy
generation in a nuclear reactor ? 1
(A) Energy is obtained by a process called nuclear fission.
(B) The nucleus of Uranium is bombarded with high energy neutrons.
(C) A chain reaction is set in the process.
(D) In this process a tremendous amount of energy is released at a
controlled rate.
OR
The biggest source of energy on Earth’s surface is 1
(A) Biomass
(B) Solar radiations
(C) Tides
(D) Winds

1
9. If a person has five resistors each of value , then the maximum
5
resistance he can obtain by connecting them is 1
(A) 1
(B) 5
(C) 10 
(D) 25 
OR

The resistance of a resistor is reduced to half of its initial value. In doing
so, if other parameters of the circuit remain unchanged, the heating
effects in the resistor will become 1

(A) two times.

(B) half.

(C) one-fourth.

(D) four times.
.31/4/2 11 P.T.O.

10. âboq_J H$m X{jU-hñV {Z`_ ~VmVm h¡ 1
(A) ào[aV Ymam H$m n[a_mU &
(B) Mwå~H$s` joÌ H$m n[a_mU &
(C) ào[aV Ymam H$s {Xem &
(D) ào[aV Ymam H$s {Xem Am¡a n[a_mU, XmoZm| &
11. {H$gr ñWbr` nm[aV§Ì H$s Hw$b àmW{_H$ CËnmXH$Vm H$m bJ^J {H$VZm ^mJ emH$mhm[a`m|
Ûmam Im`m Am¡a nMm`m OmVm h¡ ? 1
(A) 100%
(B) 10%
(C) 1%
(D) 0.1%
12. {ZåZ{b{IV _| go AgË` H$WZ Mw{ZE : 1
(A) Am°ŠgrOZ Ho$ VrZ na_mUwAm| go AmoµOmoZ H$m EH$ AUw ~ZVm h¡ &
(B) AmoµOmoZ nam~¢JZr {d{H$aUm| go n¥Ïdr Ho$ n¥îR> H$s gwajm H$aVr h¡ &
(C) AmoµOmoZ AË`ÝV {df¡br hmoVr h¡ &
(D) AmoµOmoZ nam~¢JZr {d{H$aUm| Ûmam AnK{Q>V ({d`mo{OV) hmo OmVr h¡ &
àíZ g§»`m 13 Am¡a 14 Ho$ {bE, Xmo H$WZ {XE JE h¢ {OZ_| EH$ H$mo A{^H$WZ (A) VWm Xÿgao
H$mo H$maU (R) Ûmam A§{H$V {H$`m J`m h¡ & BZ àíZm| Ho$ ghr CÎma ZrMo {XE JE H$moS>m| (a),
(b), (c) Am¡a (d) _| go MwZH$a Xr{OE &
(a) (A) Am¡a (R) XmoZm| ghr h¢ Am¡a (R), A{^H$WZ (A) H$s ghr ì`m»`m H$aVm h¡ &
(b) (A) Am¡a (R) XmoZm| ghr h¢, naÝVw (R), A{^H$WZ (A) H$s ghr ì`m»`m Zht H$aVm h¡ &
(c) (A) ghr h¡, naÝVw (R) µJbV h¡ &
(d) (A) µJbV h¡, naÝVw (R) ghr h¡ &

13. A{^H$WZ (A) : ZrMo Xr JB© A{^{H«$`m
MnO2 + 4HCl  MnCl2 + 2H2O + Cl2
aoS>m°Šg A{^{H«$`m H$m EH$ CXmhaU h¡ &
H$maU (R) : Bg A{^{H«$`m _|, HCl H$m AnM`Z Cl2 _| VWm MnO2 H$m CnM`Z
MnCl2 _| hmo OmVm h¡ & 1

.31/4/2 12

10. Fleming’s Right-hand rule gives 1
(A) magnitude of the induced current.
(B) magnitude of the magnetic field.
(C) direction of the induced current.
(D) both, direction and magnitude of the induced current.
11. How much of the net primary productivity of a terrestrial ecosystem is
eaten and digested by herbivores ? 1
(A) 100%
(B) 10%
(C) 1%
(D) 0.1%

12. Choose the incorrect statement from the following : 1
(A) Ozone is a molecule formed by three atoms of oxygen.
(B) Ozone shields the surface of the Earth from ultraviolet radiations.
(C) Ozone is deadly poisonous.
(D) Ozone gets decomposed by UV radiations.

For question numbers 13 and 14, two statements are given — one
labelled as Assertion (A) and the other labelled as Reason (R). Select the
correct answer to these questions from the codes (a), (b), (c) and (d) as
given below :
(a) Both (A) and (R) are true and (R) is the correct explanation of the
assertion (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of
the assertion (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

13. Assertion (A) : The reaction
MnO2 + 4HCl  MnCl2 + 2H2O + Cl2
is an example of a redox reaction.
Reason (R) : In this reaction, HCl is reduced to Cl2 whereas MnO2 is
oxidised to MnCl2. 1

.31/4/2 13 P.T.O.

14. A{^H$WZ (A) : {H$gr H$sQ> Ho$ n§I VWm {H$gr njr Ho$ n§I g_ê$n A§J hmoVo h¢ &
H$maU (R) : dh A§J Omo _yb g§aMZm Am¡a CËn{Îm _| H$m\$s {^Þ hmoVo h¢, naÝVw {d{^Þ
ñnrerµO _| g_mZ H$m`© H$aVo h¢, CÝh| g_ê$n A§J H$hVo h¢ & 1

IÊS> I
15. O~ H$m°na gë\o$Q> Ho$ Zrbo {db`Z go hmBS´>moOZ gë\$mBS> J¡g àdm{hV H$s OmVr h¡, Vmo
{db`Z H$m a§J \$sH$m n‹S>Zo bJVm h¡ Am¡a H$mbm Adjon àmá hmoVm h¡ &
(a) Cn`w©º$ C{ëb{IV A{^{H«$`m Ho$ àH$ma H$m Zm_ {b{IE &
(b) {db`Z H$m a§J \$sH$m Š`m| n‹S>Zo bJVm h¡ ?
(c) ~ZZo dmbo H$mbo Adjon H$m amgm`{ZH$ Zm_ {b{IE &
(d) hmoZo dmbr A{^{H«$`m H$m g§Vw{bV amgm`{ZH$ g_rH$aU Xr{OE & 3

AWdm

ZrMo {XE JE AmaoI H$m AÜ``Z H$s{OE Am¡a {ZåZ{b{IV àíZm| Ho$ CÎma Xr{OE :

(a) AmaoI _| Xem©E JE àH«$_ H$m Zm_ {b{IE &
(b) EoZmoS> Am¡a H¡$WmoS> H$m g§KQ>Z {b{IE &
(c) Bg àH$aU _| hmoZo dmbr A{^{H«$`m H$m g§Vw{bV amgm`{ZH$ g_rH$aU {b{IE &
(d) `{X Ob _| VZw gëâ`w[aH$ Aåb H$s Hw$N> ~y±X| Z {_bmE±, Vmo A{^{H«$`m Zht hmoVr &
Š`m| ? 3

.31/4/2 14

14. Assertion (A) : Wing of an insect and wing of a bird are analogous
organs.
Reason (R) : The organs which are quite different in fundamental
structure and origin but perform same function in
different species are called analogous organs. 1

SECTION B

15. When hydrogen sulphide gas is passed through a blue solution of copper
sulphate, the colour of the solution fades and a black precipitate is
obtained.
(a) Name the type of reaction mentioned above.
(b) Why does the colour of the solution fade away ?
(c) Write the chemical name of the black precipitate formed.
(d) Give the balanced chemical equation for the reaction involved. 3

OR
Study the figure given below and answer the following questions :

(a) Name the process depicted in the diagram.
(b) Write the composition of the anode and the cathode.
(c) Write the balanced chemical equation of the reaction taking place
in this case.
(d) The reaction does not take place if a few drops of dilute sulphuric
acid are not added to water. Why ? 3

.31/4/2 15 P.T.O.

16. {H$gr AdVb Xn©U H$m Cn`moJ {H$gr {~å~ H$s {d{^Þ pñW{V`m| _| CgH$m à{V{~å~ ~ZmZo
Ho$ {bE {H$`m J`m h¡ & O~ `h {~å~ 15 cm \$moH$g Xÿar Ho$ AdVb Xn©U Ho$ Y«wd go
10 cm Xÿar na aIm h¡, Vmo Bg pñW{V _| {ZåZ{b{IV Ho$ {df` _| Š`m {ZîH$f© {ZH$mbo Om
gH$Vo h¢ ?
(a) à{V{~å~ H$s pñW{V
(b) à{V{~å~ H$m gmBµO
(c) à{V{~å~ H$s àH¥${V
AnZo {ZîH$fm] H$s nw{îQ> Ho$ {bE Zm_m§{H$V {H$aU AmaoI It{ME & 3

17. {dH$mg H$s n[a^mfm {b{IE & ‘‘{dH$mg H$mo àJ{V Ho$ g_mZ Zht _mZm Om gH$Vm h¡ &’’ Bg
H$WZ H$s nw{îQ> H$s{OE & 3
AWdm
‘‘{dH$mg H$s à{H«$`m H$s Ad{Y _|, A§J AWdm bjU ZE H$m`m] Ho$ {bE AZwHy${bV hmo
gH$Vo h¢ &’’ H$moB© Cn`wº$ CXmhaU XoH$a Bg VÏ` H$s ì`m»`m H$s{OE & 3

18. _mZd eara _| CnpñWV, {ZåZ{b{IV àË`oH$ J«§{W H$s pñW{V VWm CgHo$ Ûmam òm{dV hm°_m}Zm|
Ho$ H$m`© Vm{bH$m Ho$ ê$n _| {b{IE :
(a) nr`yf JǤ{W
(b) WmBam°BS> J«§{W (AdQw> J«§{W)
(c) A½Ý`me` 3

19. `eXbonZ VWm {_lmËdZ H$s à{H«$`mAm| Ho$ ~rM VrZ {d^oXZH$mar bjUm| H$s gyMr ~ZmBE & 3

AWdm
Vm{bH$m Ho$ ê$n _| {ZåZ{b{IV YmVwAm| H$s R>§S>o Am¡a J_© Ob Ho$ gmW A{^{H«$`merbVmAm|
H$s VwbZm H$s{OE :
(a) gmo{S>`_
(b) H¡$pëg`_
(c) _¡½Zr{e`_ 3

.31/4/2 16

16. A concave mirror is used for image formation for different positions of an
object. What inferences can be drawn about the following when an object
is placed at a distance of 10 cm from the pole of a concave mirror of focal
length 15 cm ?

(a) Position of the image

(b) Size of the image

(c) Nature of the image
Draw a labelled ray diagram to justify your inferences. 3

17. Define the term evolution. ‘‘Evolution cannot be equated with progress.’’
Justify this statement. 3

OR
‘‘During the course of evolution, organs or features may be adapted for
new functions.’’ Explain this fact by choosing an appropriate example. 3

18. Write in tabular form the location and function of the hormones secreted
by each of the following glands present in the human body :

(a) Pituitary gland

(b) Thyroid gland

(c) Pancreas 3

19. List three differentiating features between the processes of galvanisation
and alloying. 3
OR

Compare in tabular form the reactivities of the following metals with cold
and hot water :
(a) Sodium
(b) Calcium
(c) Magnesium 3

.31/4/2 17 P.T.O.

20. H$m~©Z, Omo {H$ g_yh 14 H$m gXñ` h¡, AË`{YH$ g§»`m _| H$m~©Z `m¡{JH$m| H$m {Z_m©U H$aVm
h¡ {OZH$s AZw_m{ZV g§»`m bJ^J 30 bmI h¡ & Bgr JwwUY_© H$mo Bgr g_yh Ho$ AÝ` VÎd
àX{e©V Š`m| Zht H$aVo h¢ ? ì`m»`m H$s{OE & 3

21. JwéËdmZwdV©Z H$s n[a^mfm {b{IE & {H$gr nmXn Ho$ ^mJm| _| JwéËdmZwdVu J{V`m| H$mo Xem©Zo
Ho$ {bE Zm_m§{H$V AmaoI It{ME & 3

22. (a) 45 Ho$ g_mZ AmnVZ H$moU Ho$ {bE Xmo nmaXeu _mÜ`_m| P VWm Q _| AndV©Z
H$moU Ho$ _mZ H«$_e: 20 Am¡a 30 h¢ & BZ XmoZm| _| go H$m¡Z-gm _mÜ`_ A{YH$
àH$m{eH$ gKZ h¡ Am¡a Š`m| ?
(b) b|g H$s 1 S>mBAm°ßQ>a j_Vm H$s n[a^mfm {b{IE &
(c) + 0.5 D j_Vm Ho$ b|g H$s \$moH$g Xÿar kmV H$s{OE & 3

23. Amn H$m±M Ho$ Xmo gd©g_ {àµÁ_m| H$m Cn`moJ {H$g àH$ma H$a|Jo {Oggo {H$ nhbo {àµÁ_ na
Amn{VV H$moB© nVbm ídoV àH$me nw§O Xÿgao {àµÁ_ go ídoV àH$me nw§O Ho$ ê$n _| hr {ZJ©V
hmo ? {H$aU AmaoI ItMH$a Cgo Zm_m§{H$V H$s{OE & 3

24. H$moB© ì`{º$ {ZH$Q>-Ñ{îQ>> Xmof VWm XrK©-Ñ{îQ> Xmof XmoZm| go nr{‹S>V hmo gH$Vm h¡ &
(a) Bg pñW{V H$mo Š`m H$hVo h¢ ?
(b) `h pñW{V H$~ CËnÞ hmoVr h¡ ?
(c) Bg Xmof go nr{‹S>V ì`{º$`m| H$mo àm`: {Og àH$ma Ho$ b|gm| H$s Amdí`H$Vm hmoVr h¡
CgH$m Zm_ {b{IE & Bg àH$ma Ho$ b|gm| H$m Zm_m§{H$V AmaoI It{ME & 3

IÊS> J

25. {_lmVw H$s n[a^mfm {b{IE & {_lmVw {H$g àH$ma ~ZmB© OmVr h¡ ? {_lmVw ~ZmZo Ho$ Xmo bm^m|
H$s gyMr ~ZmBE & ñQ>oZbog ñQ>rb (BñnmV) H$m g§KQ>Z {b{IE & Am`aZ H$s VwbZm _|
ñQ>oZbog ñQ>rb (BñnmV) H$mo àmW{_H$Vm Š`m| Xr OmVr h¡ ? Xmo H$maUm| H$s gyMr ~ZmBE & 5

.31/4/2 18

20. Carbon, a member of group 14, forms a large number of carbon
compounds estimated to be about three million. Why is this property not
exhibited by other elements of this group ? Explain. 3

21. Define geotropism. Draw a labelled diagram of a plant showing geotropic
movements of its parts. 3

22. (a) For the same angle of incidence of 45, the refraction angle in two
transparent media P and Q is 20 and 30 respectively. Which of
the two is optically denser and why ?

(b) Define 1 dioptre power of a lens.

(c) Find the focal length of a lens of power + 0.5 D. 3

23. How will you use two identical glass prisms so that a narrow beam of
white light incident on one prism emerges out of the second prism as
white light ? Draw and label the ray diagram. 3

24. A person may suffer from both myopia and hypermetropia defects.

(a) What is this condition called ?

(b) When does it happen ?

(c) Name the type of lens often required by the persons suffering from
this defect. Draw labelled diagram of such lenses. 3

SECTION C

25. Define an alloy. How is an alloy prepared ? List two advantages of
making alloys. Write the composition of stainless steel. Why is steel
preferred over iron ? List two reasons. 5

.31/4/2 19 P.T.O.

26. {H$gr nwîn _| {ZfoMZ H$mo Xem©Zo H$m ñdÀN> AmaoI It{ME Am¡a Cg na (a) namJZbr,
(b) Za OZZ-H$mo{eH$m Am¡a (c) _mXm OZZ-H$mo{eH$m H$mo Zm_m§{H$V H$s{OE & nwîn _| {ZfoMZ
H$s à{H«$`m H$s ì`m»`m H$s{OE & {ZfoMZ Ho$ níMmV² (i) AÊS>me` Am¡a (ii) ~rOmÊS> H$m
Š`m hmoVm h¡ ? 5

AWdm
(a) `m¡dZmaå^ {H$go H$hVo h¢ ?
(b) _mZd Za OZZ V§Ì _| {ZåZ{b{IV ^mJm| Ho$ H$m`m] H$m g§jon _| dU©Z H$s{OE :
(i) d¥fU
(ii) ewH«$me`
(iii) ewH«$dm{hH$m
(iv) _yÌ_mJ©

(c) d¥fU CXa Jwhm Ho$ ~mha pñWV Š`m| hmoVo h¢ ?
(d) CëboI H$s{OE {H$ ewH«$mUw _mXm OZZ-H$mo{eH$m H$s Amoa {H$g àH$ma J{V H$aVo h¢ & 5

27. {H$gr Eogo n[anW H$m ì`dñWm AmaoI It{ME {Og_| 2 V Ho$ VrZ gobm| H$s ~¡Q>ar, nmíd© _|
g§`mo{OV 10 , 20  VWm 30  Ho$ VrZ à{VamoYH$m| H$m g§`moOZ, EH$ ßbJ Hww§$Or VWm EH$
Eo_rQ>a, g^r loUr _| g§`mo{OV h¢ & Bg n[anW H$m Cn`moJ H$aHo$ {ZåZ{b{IV H$m _mZ kmV
H$s{OE :
(a) àË`oH$ à{VamoYH$ go àdm{hV Ymam
(b) n[anW _| àdm{hV Hw$b Ymam
(c) n[anW H$m Hw$b à^mdr à{VamoY 5
AWdm
{H$gr 6 V H$s ~¡Q>ar go Xmo gd©g_ à{VamoYH$, {OZ_| àË`oH$ H$m à{VamoY 15  h¡,
~mar-~mar go nhbo (i) loUr _|, Am¡a {\$a (ii) nmíd© _| g§`mo{OV {H$E JE h¢ & àË`oH$ àH$aU
_| à{VamoYH$m| Ho$ g§`moOZ Ûmam Cn^wº$ e{º$ Ho$ AZwnmV H$m n[aH$bZ H$s{OE & 5

.31/4/2 20

26. Draw a neat diagram showing fertilisation in a flower and label (a) Pollen
tube, (b) Male germ cell and (c) Female germ cell, on it. Explain the
process of fertilisation in a flower. What happens to the (i) ovary and
(ii) ovule after fertilisation ? 5

OR

(a) What is puberty ?

(b) Describe in brief the functions of the following parts in the human
male reproductive system :

(i) Testes

(ii) Seminal vesicle

(iii) Vas deferens

(iv) Urethra

(c) Why are testes located outside the abdominal cavity ?

(d) State how sperms move towards the female germ cell. 5

27. Draw a schematic diagram of a circuit consisting of a battery of 3 cells of
2 V each, a combination of three resistors of 10 , 20  and 30 
connected in parallel, a plug key and an ammeter, all connected in series.
Use this circuit to find the value of the following :
(a) Current through each resistor
(b) Total current in the circuit
(c) Total effective resistance of the circuit 5

OR

Two identical resistors, each of resistance 15 , are connected in
(i) series, and (ii) parallel, in turn to a battery of 6 V. Calculate the ratio
of the power consumed in the combination of resistors in each case. 5
.31/4/2 21 P.T.O.

28. ß`mµO Ho$ ag _| {^JmoH$a {ZH$mbr JB© H$n‹S>o H$s {H$gr nÅ>r H$m Cn`moJ {H$gr Ðd ‘X’ Ho$
narjU Ho$ {bE {H$`m J`m & Ðd ‘X’ Zo CgH$s J§Y H$mo n[ad{V©V H$a {X`m & ß`mµO H$m ag
{H$g àH$ma H$m gyMH$ h¡ ? `hr Ðd ‘X’ Zrbo {bQ>_g H$mo bmb H$a XoVm h¡ & {ZåZ{b{IV Ho$
gmW Ðd ‘X’ H$s A{^{H«$`m Ho$ àojUm| H$mo Xem©Zo Ho$ {bE gyMr ~ZmBE :
(a) qµOH$ H$s H${UH$mE±
(b) R>mog gmo{S>`_ H$m~m}ZoQ>
hmoZo dmbr A{^{H«$`mAm| Ho$ amgm`{ZH$ g_rH$aU {b{IE & 5
AWdm
{H$ñQ>bZ Ob H$s n[a^mfm {b{IE & CXmhaUm| Ho$ ê$n _| Xmo `m¡{JH$m| Ho$ amgm`{ZH$ gyÌ
{b{IE & `h {H$g àH$ma gË`m{nV {H$`m Om gH$Vm h¡ {H$ {H«$ñQ>bZ Ob `m¡{JH$m| H$s
AdñWm Am¡a a§J _| AÝVa H$a gH$Vm h¡ ? 5

29. (a) _mZd eara Ho$ {bE nmofU Š`m| Amdí`H$ h¡ ?
(b) Amhma Zmb Ho$ ^rVa ^moOZ H$mo H$m¡Z J{V àXmZ H$aVm h¡ ?
(c) _m§gmhm[a`m| H$s VwbZm _| emH$mhm[a`m| H$s jwÐm§Ì A{YH$ bå~r Š`m| hmoVr h¡ ?
(d) `{X OR>a J«§{W`m± íboî_m H$m òdU Z H$a|, Vmo Š`m hmoJm ? 5

30. (a) gm_mÝ` Kaoby {dÚwV² n[anWm| _| g^r {dÚwV² gm{YÌm| H$mo g§`mo{OV H$aZo H$s {dYm H$m
H$maUm| g{hV C„oI H$s{OE &
(b) Kaoby {dÚwV² n[anWm| _| àm`: {H$Z Xmo n¥WH²$ n[anWm| H$m Cn`moJ {H$`m OmVm h¡ Am¡a
Eogm Š`m| {H$`m OmVm h¡ ?
(c) {H$gr {dÚwV² n[anW _| bKwnWZ H$~ hmoVm h¡ ? Bgo {H$g àH$ma amoH$m Om gH$Vm h¡ ? 5

.31/4/2 22

28. A cloth strip dipped in onion juice is used for testing a liquid ‘X’. The
liquid ‘X’ changes its odour. Which type of an indicator is onion juice ?
The liquid ‘X’ turns blue litmus red. List the observations the liquid ‘X’
will show on reacting with the following :

(a) Zinc granules

(b) Solid sodium carbonate

Write the chemical equations for the reactions involved. 5

OR

Define water of crystallisation. Give the chemical formula for two
compounds as examples. How can it be proved that the water of
crystallisation makes a difference in the state and colour of the
compounds ? 5

29. (a) Why is nutrition necessary for the human body ?

(b) What causes movement of food inside the alimentary canal ?

(c) Why is small intestine in herbivores longer than in carnivores ?

(d) What will happen if mucus is not secreted by the gastric glands ? 5

30. (a) State with reasons the mode of connecting all electrical appliances
in common domestic electric circuits.

(b) Which two separate circuits are often used in domestic electric
circuits and why ?

(c) When does an electric short circuit occur ? How can it be
prevented ? 5

.31/4/2 23 P.T.O.