CBSE QUESTION PAPER

CLASS-X

. 1 Time allowed : 2 2

hours J

Rmfur � : 2 � EfTl?: J

General Instructions :

SCIENCE (Theory)

fc4 � 1.-1 (�;;a, f..a efi)

[ Maximum marks : 60

[ 37T[[cFi7flf 3Ttfi : 60

{i) The question paper comprises of two sections, A and B. You are to . attemptb.Qtb.ihe sections.

(ii) All questions are compulsory..

(iii) There is no overall choice however; internal choice has been

provided in all the three questions of five marks category. Only one

option in such questions is to be attempted.

(iv) All questions of Section A and all questions of Section B are to be

attempted separately.

(v) Question numbers 1 to 6 in Section A and 19 to 21 in Section B are

short answer type questions. These questions carry one mark each.

(vi) Question numbers 7 to 12 in Section A and 22 to 24 in Section B are

short answer type questions q.nd carry two marks each.

(vii) Question numbers 13 to 16 in Section A and 25 and 26 in Section B

are also short answer type questions and carry three marks each.

(viii) Question numbers 17 and 18 in Section A and question number 27 in

Section B are long answer type questions and carry five marks each.

fl/4/..q �:

(i) � Sl�../4# cn1 c[T mrif, 'mTT Jl 3/h: 'mTT �, -q � 7p:rr � I 3fT4cit cffe1T mrif <f;'

"SlRf <f;' "3m � t I

{ii) tnit N;r 31Rc/14' g I

(iiiJ Tf!. >l�../4;/ qz cf>1-/ 'qlR mr:a � � qz::g tfrq-tfrq 3F:fiT <f;' rtR m -q N;r

� � � 7p:rr �I� "S!Rf-q Jfrrr � T!.cfi N;r ��cit "3m

�ii,�� wt0 g I

(iv) 3fT4cit 'mTT 31 3fh: 'mTT �-<f;' tnft "SlRf <f;' � 1l� -7!� 'mTT i/, 3frqr: TR

�m,

(v) 'mTT 31 <f;' N;r � 1 it 6 3fh: 'mTT � <f;' N;r t7&rT 19 it 21 i/, � f9TZ

� � 7!.cfi-7!.cfi 3ic,; <f;' g I

(vi) �3:r�'STRW§lTT 7 � 12 3:/R���'STRW§lTT 22 � 24 �"STR�-�

��mz3n<1cfr&t,

(vii) � 3:r � 'STR m§lTT 13 � 16 3:/R � � � 'STR m§lTT 25 3:/R 26 � 'STR '1ft

ifR-rfR � � illZ "3nU cfr& t I

{viii) � 3:r � 'STR m§lTT 17 3:/R 18 3:/R � � "cfiT 'STR m§lTT 2 7 "cfiT 'STR

C/fu-C/fu � � 3:/R � 3n<1 zj g I

Section A

�3f

1. What changes in the colour of iron nails and copper sulphate solution do

you observe after keeping the iron nails dipped in copper sulphate solution

for about 30 minutes ?

� � fcl(1�-i it �-cf;T � cf>T 30 fiRc ocfl � mR � � � �

crm � �G Rl(1� -i � "QT 'it�, q ftqJ-i � % ?

2. State two characteristic features of carbon which when put together give

rise to a large number of carbon com12ounds.

� � &1 � � �a,:run cfiT 3�@ � � � � � "&i Rl�l 1(1 B&TT -it

��%1

3. Explain why a ray of light passing through the centre of curvature of a

concave mirror gets reflected along the same path.

� chl�Q, fcnfcnm � GtfoT��� �� �m1cf;tfcRUTGtfoT�

9{1q<f-i ���tfit� �ciNB� 3fl�i I

1

1

1

1

4. What is the nature of the image formed by a concave mirror if the

magnification produced by the mirror is + 3 ?

� fcnm � � IDU � st@Rikl cnT � + 3 t al � IDU � �

Sl@RiklcfiTcRl"T�i?

5. A charged particle enters at right angles into a uniform magnetic field as

shown. What should be the nature of ch�rge on the particle if it begins to

move in a direction pointing vertically out of the page due to its interaction

with the magnetic field ?

I

; Magnetic _ Field

----------

'

Charged Particle

� 3iltjfoa cfiUT fcnm L!,ch�J.!H 1klchl� �-q @'q � � � � (1klq<l

m cfl«fT % I � 1klchl� � U � � � � ltj �Id � � � � '3'tcTTm:

"3ilR -cfi)- 3W TTm cmcn t m � ltj �,a q)Uf � � cfiT � cRlT % ?

- 1klch14

------- �

6. Name the part of our eyes that helps us to focus near and distant objects in

qui?k succession.

-i:f"Rcf��"3"B 'qflTcfil-;rn:r fafu!Q,-m'RcnGcr��wra�3itcf;T��cfl8

� Bi514dl�%1

7. What happens when an aqueous solution of sodium sulphate reacts

with an aqueous solution of barium chloride ? State the physical conditions

of reactants · in which the reaction between them will not take place. Write

the balanced chemical equation for the reaction and name the type of

reaction.

� maT % � ftl�4� � � � fcla4-1 cfiT � cf<;1l{I�� � � fcla4,1 B

� � % ? � � � cfiT 3�@ ch)f¾Q, � � GB1 �

� ffi ����%I �� cfiT l-l,t!fcid {lflll1RCh l-ltftcf1{01 fafu!Q, G�

���>fcnRcfiT-;,n:r"m�I

8. What is the main constituent of biogas ? How is biogas obtained from

biomass ? Write any two advantages of using this gas.

is114l�l-l (�fro-) cfiT� m�%? � �cl�l�I ���fcRTT7jffiff % ? �

fro-cITT 3tl7Wr cfl8 ��GT �� fa Rs! Q, I

1

2

2

9. In the figure given below a narrow beam of white light is shown to pass

through a triangular glass prism. After passing through the prism it

produces a spectrum XY on a screen.

(a) State the colour seen at X and Y.

(b) Why do different colours of white light bend through different

angles with respect to the incident beam of light ?

� � � m -q- � � ffif >lcfim cflT 1:@ffi � fcnm-&�'Jtlcnl{ ffl �

���tl������1:R1R�fqcf?4 XY�tl

y

X

(3:r) xcr�Y1Rfusm��cf0Tcfil,k8@�1

(Gf) � B � � � m >1cnm � � cfUT � fcRur � "BN�

3:,Wl-3:,WT � "CR cflll � % ?

10. What is a solenoid ? Draw the pattern of magnetic field lines of a solenoid

through which a steady current flows. What does the pattern of field lines

inside the solenoid indicate ?

qf{.:i1R-ich1 � � % ? fcnl:ft � qf{.:i1R-ich1 � ��ch1ll � oo3it cfiT tr.f @f¾o,

ftn:m�"fmm� mu sic11f%a mcft� 1 qf{.:i1R-ich1 ·� �� ��chlll �&ni

cRTT��%?

11. A coil of insulated wire is connected to a galvanometer. What would be

seen if a bar magnet with its north pole towards one face of the coil is

(i) moved quickly towards it,

(ii) moved quickly away from the coil and

(iii) placed near its one face ?

Name the phenomena involved.

fu�c(Ufucr crR B � � �u:sct) � �("�-1'1i.flc:( � � � 1 cRTT "ITT171 � � �

��"3W-�cfil �o:gct)�fcfajt��

(i) � 3ffi<®""l"fRf B��,

(ii) <fui"l"fRfB"CRWllT�, �

(iii) �HcRWWTT�?

� � � fu'Q: 3fl{G 14) >fmcf cfiT � k1 f@o, I

2

2

12. Mention any four limitations in harnessing wind energy on a large

2 scale.

� � "91: -qq;r � � �-ij � cfTffi fcf;;m � mm3TT � 31:ci@

�I

13. At what distance should an object be placed from a convex lens of focal

length 18 cm to obtain an image at 24 cm from it on the other side. What

will be the magnification produced in this case ?

18 cm����� "B fcnm � cnT � � 'R � �

� fcn � si@f¾kl � "B 24 cm c€t � 1R �? � �-ij 3TTcf¢1 fcRr.n

-mr?

14. No chemical reaction takes place when granules of a solid, A, are

mixed with the powder of another solid, B. _However when the mixture is

heated, a reaction takes place between its components. One of the

products, C, is a metal and settles down in the molten state while the other

product, D, floats over it. It was · observed that the reaction is highly

exothermic.

(i) Based on the given information make an assumption about A and B

and write a chemical equation for the chemical reaction indicating

the conditions of reaction, physical state of reactants and products

and thermal status of reaction.

(ii) Mention any two types of reactions under which above chemical

reaction can be classified.

3

3

<lo � TfllT ff; m:f\ cITTi, A,

�'1{��� 3lf���' �fif�cITTTfll�'1{��

�3lf��cTT�, C� D�%1�, C, � 'm"f!t��

������t, � �, D,��&mWcTTtl�aJOT��

� 3lf� ���1:m�I

(i) 3qi),a:; � � 3l'f'qR '1{ A am B � � � � �1111�Q. � (lf!l4Rcfi

� � � (ll-11.QRcfi Wficfi(Ot R-lf©Q. � 3lf� ��ctr

�, "fl'� 3rMcfillchl ��cfir � �m 3:fu:.3lf���

·�cfil�WTT"ITTl

(ii) � en >fcnT( ctr 3lf�;m � � R-if©q_ � 3qu,a:; 3lf� cfil

cPff't1a fcnm � ml t I

15. Name the functional group of orgamc compounds that can be

hydrogenated. With the help of suitable example explain the process of

hydrogenation mentioning the conditions of the reaction and any one

change in physical property with the formation of the product. Name any

one natural source of organic compounds that are hydrogenated.

&f cfit4Rcfi ;qlfrtch1 � �� � cfiT ;rm R-lf©o: f¾-1cfil $1$�<:il.:ftcfi(OI fcfim

� ml t I � 3Glt;(OI cf;l" l-1$1.Qcil B t;l$17<:il.f1cfi(OI ctr � l-ll.!$ll$Q, I �

��� �1ci�<-1cfi����B�c:i@�� � qf{clct-i �

Jc--fl@ 4i1�Q. l � � � swf@cfi ffl<l cfiT '-1"m R-lf©q_ � cfil4Rcfi � cfiT

t\1$17<:i!..ftcfi(OI ��i I

3

16. Atoms of eight elements A, B, C, D, E, F, G and H have the same

number of electronic shells but different number of electrons in their

outermost shell. It was found that elements A and G combine to form an

ionic compound. This compound is added in a small amount to

almost all vegetable dishes during cooking. Oxides of elements A and

B are basic in nature while those of E and F are acidic. The oxide of D is

almost neutral. Based on the above information answer the following

questions:

(i) To which group or period of the periodic table do the listed elements

belong?

. (ii) What would be the. nature of compound formed by a combination of

elements B and F ?

(iii) Which two of these elements could definitely be metals ?

(iv) Which one of the eight elements is most likely to be found in

gaseous state at room temperature ?

( v) If the number of electrons in the outermost shell of elements C and

G be 3 and 7 respectively, write the formula of the compound

fonned by the combination of C and G. 3

3lld� A, B, C, D, E, F, G� H-qB��-q �Mct�T.f) cnTfflcfr"fi"&TT

m %, � � �l&]d� �-q �Mctc;J;,l cfr "fi"&TT f�-m t I� -q-mr Tfm fcf;

·m=crA�G�zjmrr�����%Niflcfil�lfT511-q�

�WT Btjt flf;;i4l cfiT �-q fcf;m �%I rn'cf A� B � 311cffll�-s1 'cfTT �

�%,�Ea� F �.-1-lli:Ril�:S �%I m=cr D cnT �Tc:R-11�:g WT'ffl"f 3Glff).:i

% I� '51Hcfi1{). � 3ll� tR f?ti:;ifulf@a >TW � sffi: �:

(i) �lfQ;cfc'cf3lfc@tWUfit����3Tlc@t�i?

(ii) cfc'cfBomFtB-mrTB����cfllTm.fi?

(iii) � � B GT cfc'q R�a � B � m % ?

(iv) � rrQ; 3TI3 cR'cl1 -ij B � cfc'cf t cfiaJ (ffG" "CR� �m -ij � � �

"timcRT3lf�t?

(v) � cfc'cf com G � �l&-1<'11-l � -ij �= 3 om 7 �cicf?T., ITT, m �

"B-mrT 'B � � cfi"I {I fl 1./.l R ch � R,i fut Q. I

17. Write the names and symbols of two most reactive metals belonging to

group I of the periodic table. Explain by drawing electronic structure how

_either one of the two metals reacts with a halogen. With which name is the

bond formed between these elements known and what is the class of the

compound so formed known ? State any four physical properties of such

compounds.

Or

What is meant by refining of a metals ? Name the most widely used method

of refining impure metals produced by various reduction processes.

Describe with the help of a labelled diagram how this method may be used

for refining of copper.

3lfcIB � � � r � cR'cn -ij B � 3lf'cTcn fsh;q 1 � na GT �3:rr � ..,-n:r R-t fut Q.1

�cicf?IRch � � � � � � fcn � 'B cnW � mg fcnm g�l-5H B

� >1cnR 3lf� cn«ft t I� cR'cn � llUf t �q o� ��lfrlctil t � � �

-;rrq'B��t?��lfr,fcnltfcn;m��TTicf>T31:ci@·�1

5

,3l?.fq'f

�311 � qfosch{OI B � � % ? � 319·i-.P.H -� � � � �311

cn1 qf{'¥d cfi8 cRt � 3lf'llcfi S1-c1faa fcrfu cfiT ::rm faf@Q, 1 -111-1ifcha 3T,ITTg cfiT

fl�l<Qdl � cfiTIR � qf{tScfr(UI � � fcrfu cfiT � � � � 'Bcfi-aT t �

�faf©Q,I

18. Derive the expression for the heat produced due to a current 'I' flowing for

a time interval 't' through a resistor 'R' having a potential difference 'V'

across its ends. With which name is the relation known ? How much beat

will an instrument of 12W produce in one minute if it is connected to a

battery of 12V ?

Or

Explain with the help of a labelled circuit diagram how you will find

the resistance of a combination of three resistors, of resistance R 1, R2

and R3, joined in parallel. Also mention how you will connect the ammeter

and the voltmeter iI?, the circuit when measuring the current in the �ircuit

and the potential difference across one of the three resistors of the

combination.

fcR:fi>ITT!D� 'R' ��fuu�"tf'affcr� 'V' t 't' �-d-lrd{l(vl ��

mu 'I' �c11f%a fcnQ:�'R��cf@T������I �

�� 911 fcFiB ::rm���%? 12V cfiT � il fi41f¾a 12W cfiT � 39ch{0I

� � acfi ·mD Slcj 1f%a � 'R � � � �?

5

.:w:iif?F;a -q-ftq� 3tmsr cfl- B�1<-1a1 � � � fcn R1, R2 am R3 >ITTrn't:f � <fR

>lfm)� cfiT 91�4sh4 -q Bmf¾a cfl8 � � B.!.ll�H cfi"T >ITTfn'tf 3=JTtf fcF>B m �

� 1 � m � ch) N1 q_ fcn -qftq� -il st q I ft;a mu am fcR:fi "Q,cli >ITTrntTcn � ftm �

� fcr� cfit -mq � fu"Q, 3=JTtf � am cflc,-c:if)c:{ cn1 -q-ftq� � fcF>B m

B.!.llf¾a �I

Section B

��

19. Name the green dot like structures in some cells observed by a student

when a leaf peel was viewed under a microscope. What is this green colour

due to? 1

fcR:fi � � � cfi"T �&-� � �a.:fOT � � fcR:fi m5f � � cfii�lcf>l-3TT

��� ���I� �3:ncfi"T';fJ1=f k-iruJQ,l ��frr ��

'ITTffi t?

20. How is the spinal cord protected in the human body ?

21. How is the incre.asing demand for energy adversely affecting our

environment?

1

1

22. What are hormones ? Name the hormone secreted by thyroid and state its

function.

23. With the help of diagrams show the different stages of binary fission in

Amoeba.

24. Give one example each of characters that are inherited and the ones that are

acquired in humans. Mention the difference between the inherited and the

acquired characters.

"l:{'Rcf��91@� �am� ci�,1�11q �����cfll�-� 3G1$(UI

@RslQ, I 391Nta q_cf �,�ci�li:h <:1'�� �cf>T J(Y�@ ch)�Q, I

25. Write the full form of DNA. Name the part of the cell where it is located.

Explain its role in the process of reproduction of the cell.

DNA cflT � �11Ri:h � @RslQ,I � cf>l�li:hl ·i$ � m-rr � �� '%, � �

@RslQ,I cf>l�li:hl��m���� ch1�Q,I

26. Explain the phenomenon of "biological magnification." How does it affect

organisms belonging to different trophic levels particularly the tertiary

consumers?

2

2

2

3

3

'� 3llcf�' � qf{t.+6-ll m chl�Q,I fcrf� �-tr@��, f¾�ltS!ch( �

"3'1�3TT'q"{Wcfir�Wl-lfq�%?

27. Explain the process of digestion of food in mouth, stomach and small

intestine in human body.

Or

(a) · List the three events that occur during the process of photosynthesis.

Explain the role of stomata in this process.

(b) Describe an experiment to show that "sunlight 1s essential for

photosynthesis."

� � -q � (ti@�t::1), -;}tlll1�1c1 nm � -q � "9'RR � � m ·

�I

( 3l) Slchl:tlfi�citSIOI � mfill � � � � cfTffi � �3TT ���I

��-qfsn��m�I

c�> � � � � "Fcn "Slch1�,B�alSfo1 � fRL!. � 'chT >fcfim �,q�<lch �,, �

1!:cfi wwr 'chlffl � I

5