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Class 10 CBSE Board Exam 2015 : Science

24 pages, 49 questions, 28 questions with responses, 35 total responses,

CBSE 10
Kendriya Vidyalaya (KV), Kamla Nehru Nagar, Ghaziabad

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Set 1 H$moS> Z . Series RLH Code No. amob Z . 31/1 narjmWu H$moS >H$mo C ma-nwp VH$m Ho$ _wI-n >na Ad ` {bIo & Roll No. Candidates must write the Code on the title page of the answer-book. H $n`m Om M H$a b| {H$ Bg Z-n _o _w{ V n > 16 h & Z-n _| Xm{hZo hmW H$s Amoa {XE JE H$moS >Z ~a H$mo N>m C ma -nwp VH$m Ho$ _wI-n > na {bI| & H $n`m Om M H$a b| {H$ Bg Z-n _| >36 Z h & H $n`m Z H$m C ma {bIZm ew $ H$aZo go nhbo, Z H$m H $_m H$ Ad ` {bI| & Bg Z-n H$mo n T>Zo Ho$ {bE 15 {_ZQ >H$m g_` {X`m J`m h & Z-n H$m {dVaU nydm _| 10.15 ~Oo {H$`m OmEJm & 10.15 ~Oo go 10.30 ~Oo VH$ N>m Ho$db Z-n H$mo n T>|Jo Am a Bg Ad{Y Ho$ Xm amZ do C ma-nwp VH$m na H$moB C ma Zht {bI|Jo & Please check that this question paper contains 16 printed pages. Code number given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate. Please check that this question paper contains 36 questions. Please write down the Serial Number of the question before attempting it. 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. g H${bV narjm II SUMMATIVE ASSESSMENT II {dkmZ SCIENCE {ZYm [aV g_` : 3 K Q>o A{YH$V_ A H$ : 90 Time allowed : 3 hours 31/1 Maximum Marks : 90 1 P.T.O. gm_m ` {ZX}e : Bg Z n H$mo Xmo ^mJm|, ^mJ A Am a ^mJ ~, _| ~m Q>m J`m h & AmnH$mo XmoZm| ^mJm| Ho$ (i) Zm| Ho$ C ma {bIZo h & (ii) g^r Z A{Zdm` h & (iii) nyao Z n _| {H$gr Z _| H$moB M`Z m Zht h & (iv) AmnH$mo ^mJ A Am a ^mJ ~ Ho$ g^r Zm| Ho$ C ma n WH $-n WH $ ^mJ Ho$ AmYma na {bIZo h & (v) ^mJ A Ho$ Z g `m 1 go 3 Ho$ Z EH$-EH$ A H$ Ho$ h & BZHo$ C ma EH$ e X AWdm EH$ dm ` _| X| & (vi) ^mJ A Ho$ Z g `m 4 go 6 Ho$ Z Xmo-Xmo A H$m| Ho$ h & BZHo$ C ma bJ^J 30 e Xm| _| XoZo h & (vii) ^mJ A Ho$ Z g `m 7 go 18 Ho$ Z VrZ-VrZ A H$m| Ho$ h & BZHo$ C ma bJ^J 50 e Xm| _| XoZo h & (viii) ^mJ A Ho$ Z g `m 19 go 24 Ho$ Z nm M-nm M A H$m| Ho$ h & BZHo$ C ma bJ^J 70 e Xm| _| XoZo h & (ix) ^mJ ~ Ho$ Z g `m 25 go 33 Ho$ Z `moJm _H$ H$m eb na AmYm[aV ~h {dH$ nr Z h & `oH$ Z EH$ A H$ H$m h & {XE JE Mma {dH$ nm| _| go AmnH$mo Ho$db EH$ g~go Cn`w $ {dH$ n MwZZm h & (x) ^mJ ~ Ho$ Z g `m 34 go 36 Ho$ Z `moJm _H$ H$m eb na AmYm[aV Xmo-Xmo A H$m| Ho$ Z h & BZHo$ C ma g {j _| XoZo h & General Instructions : (i) The question paper comprises two Sections, A and B. You are to attempt both the sections. (ii) All questions are compulsory. (iii) There is no choice in any of the questions. (iv) All questions of Section A and all questions of Section B are to be attempted separately. (v) Question numbers 1 to 3 in Section A are one-mark questions. These are to be answered in one word or in one sentence. (vi) Question numbers 4 to 6 in Section A are two-marks questions. These are to be answered in about 30 words each. (vii) Question numbers 7 to 18 in Section A are three-marks questions. These are to be answered in about 50 words each. 31/1 2 (viii) Question numbers 19 to 24 in Section A are five-marks questions. These are to be answered in about 70 words each. (ix) Question numbers 25 to 33 in Section B are multiple choice questions based on practical skills. Each question is a one-mark question. You are to select one most appropriate response out of the four provided to you. (x) Question numbers 34 to 36 in Section B are two-marks questions based on practical skills. These are to be answered in brief. ^mJ A SECTION A 1. EWoZ Ho$ AUw _| ghg `moOr Am~ Ym| H$s g `m {b{IE & 1 Write the number of covalent bonds in the molecule of ethane. 2. {H$gr Ord Ho$ Cg O d- H $_ H$m Zm_ {b{IE Omo CgH$s g_p Q> H$s d { _| ghm`Vm H$aVm h & 1 Name the life process of an organism that helps in the growth of its population. 3. `{X {H$gr Im m Ibm Ho$ W_ nmofr Va na 10,000 Oyb D$Om Cnb Y h , Vmo { Vr` nmofr Va Ho$ Ordm| H$mo {H$VZr D$Om Cnb Y hmoJr ? 1 nd What will be the amount of energy available to the organisms of the 2 trophic level of a food chain, if the energy available at the first trophic level is 10,000 joules ? 4. H$m M Am a Ob Ho$ {Zanoj AndV Zm H$ H $_e: 4/3 Am a 3/2 h & `{X H$m M _| H$me H$s Mmb 2 108 m/s h , Vmo (i) {Zdm V, (ii) Ob _| H$me H$s Mmb n[aH${bV H$s{OE & 2 The absolute refractive indices of glass and water are 4/3 and 3/2 respectively. If the speed of light in glass is 2 108 m/s, calculate the speed of light in (i) vacuum, (ii) water. 5. J Jm ZXr Ho$ Ob Ho$ X {fV hmoZo Ho$ Xmo _w ` H$maUm| H$s gyMr ~ZmBE & C boI H$s{OE {H$ {H$gr ZXr Ho$ Ob H$m Xy{fV Am a g Xy{fV hmoZm CgHo$ Amg-nmg Ho$ jo m| _| ahZo dmbo bmoJm| Ho$ dm ` Ho$ {bE hm{ZH$a `m| {g hmoVm h & 2 List two main causes of the pollution of water of the river Ganga. State how pollution and contamination of river water prove harmful for the health of the people of neighbouring areas. 31/1 3 P.T.O. 6. O d {d{dYVm {H$go H$hVo h ? `{X {H$gr jo H$s O d {d{dYVm gwa{jV Zht aIr OmE, Vmo `m hmoJm ? BgHo$ EH$ ^md H$m C boI H$s{OE & 2 What is biodiversity ? What will happen if biodiversity of an area is not preserved ? Mention one effect of it. 7. {H$gr Eo H$mohm b Am a H$m~m op g{bH$ A b _| ^oX H$aZo Ho$ Xmo m`mo{JH$ narjUm| H$s gyMr ~ZmBE Am a dU Z H$s{OE {H$ `o narjU H $go {H$E OmVo h & 3 List two tests for experimentally distinguishing between an alcohol and a carboxylic acid and describe how these tests are performed. 8. EWmBZ H$s Bbo Q >m Z-{~ X g aMZm H$m {M U H$s{OE & EWmBZ Am a Am grOZ Ho$ {_lU H$m XhZ dop S> J Ho$ {bE {H$`m OmVm h & AmnHo$ {dMma go Bg H$m` Ho$ {bE EWmBZ Am a dm`w Ho$ {_lU H$m Cn`moJ `m| Zht {H$`m Om gH$Vm h ? 3 Draw the electron-dot structure for ethyne. A mixture of ethyne and oxygen is burnt for welding. In your opinion, why cannot we use a mixture of ethyne and air for this purpose ? 9. Xmo V d P Am a Q AmYw{ZH$ AmdV gmaUr Ho$ EH$ hr AmdV Ho$ H $_e: g_yh-1 Am a g_yh-2 Ho$ gX ` h & BZHo$ {Z Z{b{IV bjUm|/JwUY_m o H$s Vm{bH$m Ho$ $n _| VwbZm H$s{OE : (a) BZHo$ na_mUwAm| _| Bbo Q >m Zm| H$s g `m (b) BZHo$ na_mUwAm| H$m gmB O (c) BZH$s Ymp dH$ d { m (d) BZH$s Bbo Q >m Z `mJZo H$s d { m (e) BZHo$ Am gmBS>m| Ho$ gy (f) BZHo$ bmoamBS>m| Ho$ gy Two elements P and Q be ong to the sa e period of the modern periodic table and are in Group-1 and Group-2 respectively. Compare their following characteristics in tabular form : (a) (b) The sizes of their atoms (c) Their metallic characters (d) Their tendencies to lose electrons (e) The formula of their oxides (f) 31/1 The number of electrons in their atoms The formula of their chlorides 4 3 10. na_mUw H $_m H$ 16 Ho$ V d H$m CXmhaU boH$a n Q> H$s{OE {H$ AmYw{ZH$ AmdV gmaUr _| {H$gr V d H$m WmZ Cg V d Ho$ na_mUw Ho$ Bbo Q >m {ZH$ {d `mg go {H$g H$ma g ~p YV hmoVm h VWm {H$gr V d Ho$ na_mUw H $_m H$ Ho$ AmYma na CgH$s g `moOH$Vm {H$g H$ma n[aH${bV H$s OmVr h & 3 Taking the example of an element of atomic number 16, explain how the electronic configuration of the atom of an element relates to its position in the modern periodic table and how valency of an element is calculated on the basis of its atomic number. 11. b {JH$ OZZ Ho$ N>: {d{e Q> A{^bjUm| H$s gyMr ~ZmBE & 3 List six specific characteristics of sexual reproduction. 12. JwUgy `m hmoVo h ? n Q> H$s{OE {H$ b {JH$ OZZ H$aZo dmbo Ordm| _| nr T>r Xa nr T>r g V{V _| JwUgy m| H$s g `m {H$g H$ma g_mZ ~Zr ahVr h & 3 What are chromosomes ? Explain how in sexually reproducing organisms the number of chromosomes in the progeny is maintained. 13. {H$gr g_mO Ho$ {bE OZZ dm ` Ho$ Mma _h d Ho$ {~ X Am| H$s gyMr ~ZmBE & h_mao Xoe _| {nN>bo 50 dfm o _| OZZ dm ` go g ~p YV {OZ jo m| _| gwYma h Am h , CZ_| go {H$ ht Xmo Ho$ Zm_ {b{IE & 3 List four points of significance of reproductive health in a society. Name any two areas related to reproductive health which have improved over the past 50 years in our country. 14. `oH$ Ho$ {bE EH$-EH$ CXmhaU XoH$a, `m `m H$s{OE {H$ {Z Z{b{IV {H$g H$ma Ordm| Ho$ {dH$mg Ho$ nj _| _mU VwV H$aVo h : (a) g_OmV A J (b) g_ $n A J (c) Ordm _ 3 Explain with an example for each, how the following provides evidences in favour of evolution in organisms : (a) (b) Analogous organs (c) 31/1 Homologous organs Fossils 5 P.T.O. 15. {Z Z{b{IV H$mo n Q> H$s{OE : (a) Om{V-CX ^dZ (b) mH ${VH$ daU (M`Z) 3 Explain the following : (a) (b) 16. Speciation Natural Selection `{X H$moB Xn U CgHo$ gm_Zo H$ht ^r p WV {~ ~ H$m gX d hr grYm Am a gmB O _| N>moQ>m {V{~ ~ ~ZmVm h , Vmo dh Xn U {H$g H$ma H$m h ? AnZo C ma H$s nwp Q> Ho$ {bE EH$ {H$aU AmaoI It{ME & Bg H$ma Ho$ Xn U m`: H$hm Am a `m| Cn`moJ {H$E OmVo h ? 3 If the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it ? Draw a ray diagram to justify your answer. Where and why do we generally use this type of mirror ? 17. H$me Ho$ H$sU Z go `m Vm n` h ? Bg n[aKQ>Zm H$s ghm`Vm go `m `m H$s{OE {H$ d N> AmH$me H$m a J Zrbm `m| VrV hmoVm h AWdm gy`m}X` Ho$ g_` gy` a $m^ `m| VrV hmoVm h & 3 What is meant by scattering of light ? Use this phenomenon to explain why the clear sky appears blue or the sun appears reddish at sunrise. 18. O d-{Z ZrH$aUr` Am a AO d-{Z ZrH$aUr` nXmWm o Ho$ ~rM `oH$ H$m EH$ CXmhaU XoH$a {d^oXZ H$s{OE & CZ Xmo AmXVm| _| n[adV Z H$s gyMr ~ZmBE {O h| n`m daU H$mo ~MmZo Ho$ {bE, `{ $ AO d-{Z ZrH$aUr` An{e Q>m| Ho$ {ZnQ>mam H$aZo _| AnZm gH$Vo h & 3 Differentiate between biodegradable and non-biodegradable substances with the help of one example each. List two changes in habit that people must adopt to dispose non-biodegradable waste, for saving the environment. 19. gm~wZ VWm An_mO H$ XmoZm| hr EH$ H$ma Ho$ bdU h & BZ_ o `m A Va h ? gm~wZ H$s g \$mB H$s {H $`m H$m g jon _| dU Z H$s{OE & gm~wZ H$R>moa Ob _| PmJ H$m {Z_m U `m| Zht H$aVo ? gm~wZm| H$s VwbZm _| An_mO H$m| H$m Cn`moJ H$aZo go C n Xmo g_ `mAm| H$s gyMr ~ZmBE & Both soap and detergent are some type of salts. What is the difference between them ? Describe in brief the cleansing action of soap. Why do soaps not form lather in hard water ? List two problems that arise due to the use of detergents instead of soaps. 31/1 6 5 (a) _mZd Za Ho$ Cg OZZm J H$m Zm_ {b{IE Omo ewH $mUwAm| Ho$ C nmXZ Ho$ gmW-gmW hm _m}Z ^r m{dV H$aVm h & m{dV hm _m}Z Ho$ H$m` {b{IE & (b) 20. _mZd _mXm Ho$ OZZ V Ho$ Cg ^mJ H$m Zm_ {b{IE Ohm (i) {ZfoMZ hmoVm h , (ii) {Zfo{MV A S>o H$m AmamonU hmoVm h & n Q> H$s{OE {H$ _mVm Ho$ eara Ho$ ^rVa ^ yU H$m nmofU {H$g H$ma hmoVm h & 5 (a) Name the human male reproductive organ that produces sperms and also secretes a hormone. Write the functions of the secreted hormone. (b) Name the parts of the human female reproductive system where (i) fertilisation takes place, (ii) implantation of the fertilised egg occurs. Explain how the embryo gets nourishment inside the mother s body. 21. _|S>b Ho$ `moJ Zo `h {H$g H$ma Xem `m {H$ bjU ^mdr AWdm A ^mdr hmoVo h , (a) (b) {d{^ bjU dV $n go d emZwJV hmoVo h ? 5 How do Mende s experi ents show that the (a) (b) 22. traits may be dominant or recessive, traits are inherited independently ? {H$gr b|g H$s j_Vm go `m Vm n` h ? BgHo$ S.I. _m H$ H$s n[a^mfm {b{IE & AmnHo$ nmg Xmo b|g A Am a B h {OZH$s \$moH$g X [a`m H $_e: +10 cm Am a 10 cm h & BZ XmoZm| b|gm| H$s H ${V {b{IE Am a j_Vm kmV H$s{OE & BZ XmoZm| _| go {H$g b|g go {H$gr {~ ~ H$mo b|g go 8 cm X ar na aIZo na CgH$m Am^mgr Am a Amd{Y V {V{~ ~ ~ZoJm ? AnZo C ma H$s nwp Q> Ho$ {bE EH$ {H$aU AmaoI It{ME & 5 What is meant by power of a lens ? Define its S.I. unit. You have two lenses A and B of focal lengths +10 cm and 10 cm respectively. State the nature and power of each lens. Which of the two lenses will form a virtual and magnified image of an object placed 8 cm from the lens ? Draw a ray diagram to justify your answer. 31/1 7 P.T.O. 23. \$moH$g X ar Ho$ {H$gr C mb b|g Ho$ AmYo ^mJ H$mo H$mbo H$m J O go T>H$ {X`m J`m h & `m `h b|g 30 cm X ar na p WV {~ ~ H$m nyam {V{~ ~ ~Zm gH$Vm h ? AnZo C ma H$s nwp Q> Ho$ {bE EH$ {H$aU AmaoI It{ME & 10 cm H$moB 4 cm b ~m {~ ~ 20 cm \$moH$g X ar Ho$ {H$gr C mb b|g Ho$ _w ` Aj Ho$ b ~dV aIm h & {~ ~ H$s b|g go X ar 15 cm h & {V{~ ~ H$s H ${V, p W{V Am a gmB O kmV H$s{OE & 5 One half of a convex lens of focal length 10 cm is covered with a black paper. Can such a lens produce an image of a complete object placed at a distance of 30 cm from the lens ? Draw a ray diagram to justify your answer. A 4 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 15 cm. Find the nature, position and size of the image. 24. _mZd Zo _| n _m^r no{e`m| H$m _h d {b{IE & Cg p Q> Xmof H$m Zm_ {b{IE Omo d md Wm _| n _m^r no{e`m| Ho$ Yrao-Yrao X ~ b hmoZo Ho$ H$maU C n hmoVm h & Bg Xmof go nr{ S>V `{ $`m| H$mo gw n Q> XoI gH$Zo Ho$ {bE {H$g H$ma Ho$ b|gm| H$s Amd `H$Vm hmoVr h ? Aj` AnZr H$jm _| A {V_ n { $ _| ~ R>o h E, b H$~moS> na {bIo e Xm| H$mo n Q> Zht XoI nm ahm Wm & O go hr {ejH$ _hmoX` H$mo nVm Mbm C hmo Zo H$jm _| KmofUm H$s, {H$ `m nhbr n { $ _| ~ R>m h Am H$moB N>m Aj` go AnZr grQ> ~XbZm MmhoJm ? gb_mZ Vwa V hr AnZr grQ> Aj` go ~XbZo Ho$ {bE V `ma hmo J`m & A~ Aj` H$mo b H$~moS> na {bIm h Am n Q> {XImB XoZo bJm & `h XoIH$a {ejH$ _hmoX` Zo Aj` Ho$ _mVm-{nVm H$mo g Xoe ^oOm {H$ do erK hr Aj` Ho$ Zo m| H$m narjU H$admE & Cn`w $ KQ>Zm Ho$ g X^ _|, {Z Z{b{IV Zm| Ho$ C ma Xr{OE : (a) (b) {ejH$ _hmoX` Am a gb_mZ mam X{e V _y `m| H$m C boI H$s{OE & (c) 31/1 Aj` {H$g p Q> Xmof go nr{ S>V h b og Cn`moJ {H$`m OmVm h ? AmnHo$ {dMma go Aj` H$mo {ejH$ _hmoX` Am a gb_mZ Ho$ {V AnZr H $VkVm {H$g H$ma H$Q> H$aZr Mm{hE ? ? 8 Bg Xmof Ho$ g emoYZ Ho$ {bE {H$g H$ma H$m 5 Write the importance of ciliary muscles in the human eye. Name the defect of vision that arises due to gradual weakening of the ciliary muscles in old age. What type of lenses are required by the persons suffering from this defect to see the objects clearly ? Akshay, sitting in the last row in his class, could not see clearly the words written on the blackboard. When the teacher noticed it, he announced if any student sitting in the front row could volunteer to exchange his seat with Akshay. Salman immediately agreed to exchange his seat with Akshay. He could now see the words written on the blackboard clearly. The teacher thought it fit to send the message to Akshay s parents advising them to get his eyesight checked. In the context of the above event, answer the following questions : (a) Which defect of vision is Akshay suffering from ? Which type of lens is used to correct this defect ? (b) State the values displayed by the teacher and Salman. (c) In your opinion, in what way can Akshay express his gratitude towards the teacher and Salman ? ^mJ ~ SECTION B 25. O~ Amn Eogr{Q>H$ A b H$mo bmb Am a Zrbo {bQ>_g n m| na S>mbVo h , V~ `m ojU H$aVo h ? (A) bmb {bQ>_g bmb hr ahVm h Am a Zrbm {bQ>_g bmb hmo OmVm h & (B) bmb {bQ>_g Zrbm hmo OmVm h Am a Zrbm {bQ>_g Zrbm hr ahVm h & (C) bmb {bQ>_g Zrbm hmo OmVm h Am a Zrbm {bQ>_g bmb hmo OmVm h & (D) bmb {bQ>_g a JhrZ hmo OmVm h Am a Zrbm {bQ>_g Zrbm hr ahVm h & 1 What do we observe on pouring acetic acid on red and blue litmus papers ? (A) (B) Red litmus turns blue and blue litmus remains blue. (C) Red litmus turns blue and blue litmus turns red. (D) 31/1 Red litmus remains red and blue litmus turns red. Red litmus becomes colourless and blue litmus remains blue. 9 P.T.O. 26. gm~wZ ~ZmVo g_` m`: dZ n{V Vob Am a gmo{S>`_ hmBS >m gmBS> Ho$ A{^{H $`m {_lU _| Wmo S>r _m m _| gmYmaU Z_H$ {_bm`m OmVm h & gmYmaU Z_H$ {_bmZo H$m {Z Z{b{IV _| go `m C o ` hmo gH$Vm h ? (A) gm~wZ H$s jmar` H ${V H$mo KQ>mZm (B) gm~wZ H$mo CXmgrZ ~ZmZm (C) gm~wZ H$s g \$mB H$s j_Vm H$mo ~ T>mZm (D) gm~wZ Ho$ AdjonU _| ghm`Vm H$aZm 1 While preparing soap a small quantity of common salt is generally added to the reaction mixture of vegetable oil and sodium hydroxide. Which one of the following may be the purpose of adding common salt ? To reduce the basic nature of the soap (A) (B) To make the soap neutral (C) To enhance the cleansing power of the soap (D) To favour the precipitation of the soap 27. H$moB N>m Mma naIZ{b`m| P, Q, R Am a S _|, `oH$ _| bJ^J 4 mL AmgwV Ob boH$a naIZbr P _| gmo{S>`_ g \o$Q>, Q _| nmoQ> {e`_ g \o$Q>, R _| H $p e`_ g \o$Q> Am a S _| _ Zr{e`_ g \o$Q> H$s g_mZ _m m H$mo `oH$ _| KmobVm h & BgHo$ n MmV dh `oH$ naIZbr _| gm~wZ Ho$ {db`Z H$s g_mZ _m m {_bmVm h & BZ g^r naIZ{b`m| H$mo ^br-^m {V {hbmZo na, dh ZrMo Xr J`r {H$Z naIZ{b`m| _| H$m\$s _m m _| PmJ H$m ojU H$aVm h ? P Am a Q (A) (B) Q Am a R (C) P, Q Am a S (D) P, R Am a S A student takes about 4 mL of distilled water in four test tubes marked P, Q, R and S. He then dissolves in each test tube an equal amount of one salt in one test tube, namely sodium sulphate in P, potassium sulphate in Q, calcium sulphate in R and magnesium sulphate in S. After that he adds an equal amount of soap solution in each test tube. On shaking each of these test tubes well, he observes a good amount of lather (foam) in the test tubes marked (A) P and Q (B) Q and R (C) P, Q and S (D) P, R and S 31/1 10 1 28. {H$gr {d mWu go amO_m Ho$ ~rO Ho$ ^ yU H$m ojU H$aHo$ CgHo$ {d{^ ^mJm| H$s nhMmZ H$aZo H$mo H$hm J`m & CgZo ^y U Ho$ ^mJm| H$mo nhMmZ H$a ZrMo Xr J`r gyMr ~ZmB : I. A V:H$dM II. ~rO Mmob III. ~rOn IV. _ybm Hw$a V. m Hw$a BZ_| go ghr nhMmZo JE ^mJ h (A) I, II Am a III (B) II, III Am a IV (C) III, IV Am a V (D) 1 : I, III, IV Am a V A student was asked to observe and identify the various parts of an embryo of a red kidney bean seed. He identified the parts and listed them as under : I. Tegmen II. Testa III. Cotyledon IV. Radicle V. Plumule The correctly identified parts among these are (A) (B) II, III and IV (C) III, IV and V (D) 31/1 I, II and III I, III, IV and V 11 P.T.O. 29. ZrMo ~m Oma _| Cnb Y Hw$N> gp O`m| H$s gyMr Xr J`r h & BZ_| go CZ Xmo gp O`m| H$mo Mw{ZE {OZH$s g aMZmE g_OmV hm| : Amby, eH$aH $X, AXaH$, _ybr, Q>_mQ>a, JmOa, {^ S>r (A) Amby Am a eH$aH $X (B) _ybr Am a JmOa (C) {^ S>r Am a eH$aH $X (D) Amby Am a Q>_mQ>a 1 Given below is the list of vegetables available in the market. Select from these the two vegetables having homologous structures : Potato, sweet potato, ginger, radish, to ato, carrot, okra (Lady s finger) (A) (B) Radish and carrot (C) Okra and sweet potato (D) 30. Potato and sweet potato Potato and tomato H$moB N>m AnZo {d mb` H$s `moJembm _| {XE JE AdVb Xn U H$s \$moH$g X ar kmV H$aVo g_` Xn U (M) mam `moJembm H$s X a W {I S>H$s (W) H$m n Q> {V{~ ~ nX o (S) na m H$aVm h & Xn U H$s \$moH$g X ar kmV H$aZo Ho$ {bE Cgo H$m Z-gr X ar _mnZr Mm{hE ? (A) (B) MS (C) SW (D) 31/1 MW MW MS 12 1 A student obtains a sharp image of the distant window (W) of the school laboratory on the screen (S) using the given concave mirror (M) to determine its focal length. Which of the following distances should he measure to get the focal length of the mirror ? (A) (B) MS (C) SW (D) 31. MW MW {H$gr N>m Zo ZrMo {XE JE AmaoI _| Xem E AZwgma EH$ ^br-^m {V Xr X a W ^dZ H$m {V{~ ~ nX o (S) na \$moH${gV H$aZo Ho$ {bE {H$gr `w{ $ (X) H$m Cn`moJ {H$`m & Bg `w{ $ (X) Ho$ {df` _| ghr H$WZ Mw{ZE & (A) (B) (C) (D) 31/1 MS `h `w{ $ 8 cm \$moH$g `h `w{ $ 8 cm \$moH$g `h `w{ $ 4 cm \$moH$g `h `w{ $ 8 cm \$moH$g X ar H$m X ar H$m X ar H$m X ar H$m 1 AdVb b|g h & C mb Xn U h & C mb b|g h & C mb b|g h & 13 P.T.O. A student used a device (X) to obtain/focus the image of a well illuminated distant building on a screen (S) as shown below in the diagram. Select the correct statement about the device (X). (A) (B) This device is a convex mirror of focal length 8 cm. (C) This device is a convex lens of focal length 4 cm. (D) 32. This device is a concave lens of focal length 8 cm. This device is a convex lens of focal length 8 cm. H$moB N>m H$m M H$s Am`VmH$ma {g r go hmoH$a Jw OaZo dmbr H$me {H$aU H$m nW AmnVZ H$moUm| Ho$ {d{^ _mZm| Ho$ {bE Amao{IV H$aVm h & dh `moJ Ho$ `oH$ MaU H$mo H$aVo g_` `Wmg ^d gmdYm{Z`m ~aVVm h & `moJ Ho$ A V _|, _mnm| H$m {d bofU H$aZo na, {Z Z{b{IV _| go CgH$m g ^m{dV {Z H$f `m hmoZm Mm{hE ? (A) (B) (C) (D) i = e< r i < e< r i > e> r i = e> r A student traces the path of a ray of light through a rectangular glass slab for the different values of angle of incidence. He observes all possible precautions at each step of the experiment. At the end of the experiment, on analysing the measurements, which of the following conclusions is he likely to draw ? (A) (B) (C) (D) 31/1 i = e< r i < e< r i > e> r i = e> r 14 1 33. H$moB N>m AmnVZ H$moU Ho$ {d{^ _mZm| Ho$ {bE H$m M Ho$ { ^wOmH$ma { _ go hmoH$a Jw OaZo dmbr H$me {H$aU H$m nW Amao{IV H$aVm h & H$me {H$aU AmaoIm| H$m {d bofU H$aZo na Cgo {Z Z{b{IV _| go H$m Z-gm {Z H$f {ZH$mbZm Mm{hE ? (A) {ZJ V {H$aU Amn{VV {H$aU Ho$ g_m Va hmoVr h & (B) {ZJ V {H$aU Amn{VV {H$aU H$s {Xem go {H$gr H$moU na _w S> OmVr h & (C) {ZJ V {H$aU Am a And{V V {H$aU EH$-X gao go g_H$moU ~ZmVr h & (D) {ZJ V {H$aU Amn{VV {H$aU Ho$ b ~dV hmoVr h & 1 A student traces the path of a ray of light through a triangular glass prism for different values of angle of incidence. On analysing the ray diagrams, which one of the following conclusions is he likely to draw ? (A) The emergent ray is parallel to the incident ray. (B) The emergent ray bends at an angle to the direction of the incident ray. (C) The emergent ray and the refracted ray are at right angles to each other. (D) 34. The emergent ray is perpendicular to the incident ray. O~ Amn EH$ naIZbr _| Eogr{Q>H$ A b boH$a Cg_| gmo{S>`_ hmBS >moOZ H$m~m oZoQ> {_bmVo h , V~ Vwa V hr Vrd ~wX~wXmhQ> Ho$ gmW H$moB J g {ZH$bVr h & Bg J g H$m Zm_ {b{IE & Bg J g Ho$ narjU H$s {d{Y H$m dU Z H$s{OE & 2 When you add sodium hydrogen carbonate to acetic acid in a test tube, a gas liberates immediately with a brisk effervescence. Name this gas. Describe the method of testing this gas. 35. N>m m| go `r Q> _| _wHw$bZ Ho$ {d{^ MaUm| H$mo Xem Zo dmbr Wm`r bmBS>m| H$m gy _Xeu H$s C j_Vm _| ojU H$aZo Ho$ {bE H$hm J`m & (a) bmBS>m| H$mo \$moH$g H$aZo Ho$ {bE AmnH$mo gy _ g_m`moOZ AWdm $j g_m`moOZ _| go {H$go Kw_mZo Ho$ {bE H$hm J`m ? (b) `r Q> _| _wHw$bZ H$mo ghr H $_ _| Xem Zo Ho$ {bE VrZ AmaoI It{ME & 2 Students were asked to observe the permanent slides showing different stages of budding in yeast under high power of a microscope. (a) (b) 31/1 Which adjustment screw (coarse/fine) were you asked to move to focus the slides ? Draw three diagrams in correct sequence showing budding in yeast. 15 P.T.O. 36. {H$gr C mb b|g Ho$ _w ` Aj na b|g Ho$ H$m{eH$ Ho$ go 12 cm X ar na H$moB 4 cm b ~m {~ ~ p WV h & b|g go 24 cm X ar na b|g Ho$ X gar Amoa Bg {~ ~ H$m Vr U {V{~ ~ EH$ nX} na ~Z ahm h & A~ `{X Bg {~ ~ H$mo b|g go Hw$N> X a bo OmE , Vmo {~ ~ H$m Vr U {V{~ ~ nX o na {\$a m V H$aZo Ho$ {bE nX o H$mo {H$g {Xem _| (b|g H$s Amoa AWdm b|g go X a) bo OmZm hmoJm ? {V{~ ~ Ho$ AmdY Z na BgH$m `m ^md hmoJm ? A 4 cm tall object is placed on the principal axis of a convex lens. The distance of the object from the optical centre of the lens is 12 cm and its sharp image is formed at a distance of 24 cm from it on a screen on the other side of the lens. If the object is now moved a little away from the lens, in which way (towards the lens or away from the lens) will he have to move the screen to get a sharp image of the object on it again ? How will the magnification of the image be affected ? 31/1 16 2 S trictly C onfidential- (For Internal and Restricted Use Only) Secondary School Examination SUMMATIVE ASSES SMENT - II March 2015 Marking Scheme Science (Outside Delhi) 31/ 1 1. The Marking S cheme provides general guidelines to reduce subjectivity in the marking. It carries only suggested value points for the answer. These are only guidelines and do not constitute the complete answer. Any other individual response with suitable justification should also be accepted even if there is no reference to the text. 2. Evaluation is to be done as per instructions provided in the Marking S cheme. It should not be done according to one's own interpretation or any other consideration. Marking S cheme should be strictly adhered to and religiously followed. 3. If a question has parts, please award marks in the right hand side for each part. Marks awarded for different parts of the question should then be totalled up and written in the left hand margin. 4. If a question does not have any parts, marks be awarded in the left hand side margin. 5. If a candidate has attempted an extra question, marks obtained in the question attempted first should be retained and the other answer should be scored out. 6. Wherever only two/ three of a 'given' number of examples/ factors/ points are expected only the first two/ three or expected number should be read. The rest are irrelevant and should not be examined. 7. There should be no effort at 'moderation' of the marks by the evaluating teachers. The actual total marks obtained by the candidate may be of no concern of the evaluators. 8. All the Head Examiners / Examiners are instructed that while evaluating the answer scripts, if the answer is found to be totally incorrect, the (X) should be marked on the incorrect answer and awarded 0 marks. 9. mark may be deducted if a candidate either does not write units or writes wrong units in the final answer of a numerical problem. 10. A full scale of mark 0 to 100 has to be used. Please do not hesitate to award full marks if the answer deserves it. 11. As per orders of the Hon ble S upreme Court the candidates would now be permitted to obtain photocopy of the Answer Book on request on payment of the prescribed fee. All Examiners/Head Examiners are once again reminded that they must ensure that evaluation is carried out strictly as per value points given in the marking scheme. Outside Delhi 31/ 1 Page 1 MARKING SC HEME C LASS X OUTSIDE DELHI C ode No. 31/ 1 Marks Total Expected Answer/ Value point SEC TION A Q1. Seven 1 1 Q2. Reproduction 1 1 Q3. 1000 J 1 1 Q4. ng i) ng c g c n g g ii) nw nw 4 ; 3 3 ; 2 g 2 10 8 m/s 4 2 10 8 m/s = 2.67 10 8 m/s 3 2.67 2 10 8 c 1.78 10 8 m/s nw 3 Note: Full marks to be awarded for those who attempt with the correct values of refractive indices. Q6. Q7. c w w Q5. 1 2 Causes: Disposal of industrial effluents Human activities like bathing, washing, immersion of ashes, etc. Disposal of untreated sewage (any two) Harmful effects on health Spreads water borne diseases, - Consumptions of contaminated fishes (or any other relevant affect) , 2 Biodiversity - number and range of variety of species of life forms in an area Effect loss of diversity may lead to a loss of ecological stability 1 1 2 Test 1 (Litmus Test) , Take two strips of blue litmus paper. Place a drop each of the alcohol and carboxylic acid on these strips separately. The blue litmus paper turns red in the case of carboxylic acid and remains unaffected in the case of alcohol. 1 Test 2 (Sodium hydrogen carbonate test / sodium carbonate test) A pinch of sodium hydrogen carbonate or sodium carbonate is added, to both separately. If brisk effervescence with the evolution of a colorless gas is Outside Delhi 31/ 1 1 Page 2 observed, it indicates the presence of carboxylic acid. If no change is observed then it confirms the presence of the alcohol. Test 3 Ester test or any other suitable test 3 (any two) Q8. 1 In pure oxygen, ethyne undergoes complete combustion and high temperature suitable for welding is attained. Whereas air contains less percentage /amount of oxygen which results in incomplete combustion of ethyne and the temperature required for welding is not attained. Q9. Property (a) No. of electrons in the atom (b) (c) (d) (e) (f) Q10. P 1 1 3 3 Q 3 11 19 4 12 20 (any one pair) Size of the atom Bigger Smaller Metallic character More metallic Less metallic Tendency to lose electrons More Less Formula of oxides P2O QO Formula of chlorides PCl QCl2 Note: For parts (e) and (f) examples using symbols of elements may also be accepted. Electronic configuration of element with atomic no. 16 is 2,8,6. Since it has 3 shells, the period no. will be 3. Since the no. of valence electrons is 6, the group no. will be 10 + 6 = 16. Valency of the element will be 8- valence electrons ie 8 6 = 2. 1 1 3 Q11. Characteristics: Two parents are involved, Two dissimilar gametes are formed, gamete formation involves meiosis, Variations are produced, Occurs in all the higher and some of the lower organisms, Fertilization / fusion of gametes leading to zygote formation Slow. x6 Outside Delhi 31/ 1 3 Page 3 Q12. Chromosomes thread like structures made up of DNA found in the nucleus. The original number of chromosomes becomes half during gamete formation. Hence, when the gametes combine, the original number of chromosomes gets restored in the progeny. (or same thing explained in the form of a flow chart). Q13. Significance prevent STDs, Advantage of small family, Less mortality among new borns, Reduces the cases of maternal mortality. 1 1,1 3 x4 Areas which have improved Family Planning, - Decrease in STD cases (any other) Q14. Homologous organs study of homologous organs suggests that the organs having same structure but performing different functions have evolved from a common ancestor. Ex. - forelimbs of a frog, lizard, bird and man. x2 Analogous organs show adoption of organs for common use. Ex. wings of butterfly and wings of bat. Fossils provide the missing links between two species. Ex. Archeopteryx / fossils of some dinosaurs with feathers. Speciation evolution of a new species from pre-existing species Occurring due to accumulation of variations By processes like genetic drift / geographical barriers like mountains, rivers etc., leading to incapability to reproduce amongst themselves in the population. 3 3 3 Natural selection Change in frequency of some genes in a population Which give survival advantage to a species from elimination. Ex. in a population of beetles, a new variation (green colour) get survival benefit / advantage to green beetles whereas other (red) perishes. Q15. 3 Outside Delhi 31/ 1 3 Page 4 Q16. Convex mirror 1 Use: Why: As rear view mirror in vehicles/ Also in Malls, Hotels, Airports for security reasons. Forms erect image, Wider field of view. Scattering Phenomenon of spreading of light (diffused reflected light) caused by minute particles (dust, smoke etc.) in the atmosphere. (ii) Sky appears blue because blue color of sunlight scatters more strongly (due to shorter wavelength) than the red color by the fine particles in the air. OR At sunrise the blue color of sunlight get scattered due to smaller wave length while passing through the thicker layers of the atmosphere. The red component (due to longer wavelength) reaches us, giving red appearance, of the Sun. Note: If explained by following diagram (fully labeled) give full credit. 3 Q17. (i) Q18. Biodegradable substances can be broken down into simpler substances by nature / decomposers/ bacteria/ saprophytes/ saprobionts. Ex. Human Excreta/ Vegetable peels, etc. (any one) Non-biodegradable substances can t be broken down into simpler substances by nature / decomposers. Ex. Plastic/ glass (or any other) (any one) Habits: - Use of separate dustbins for biodegradable and non biodegradable waste, - Reuse of things such as poly-bags, etc., - Recycle of waste - Use of cotton /jute bags for carrying vegetables etc. (any two) Outside Delhi 31/ 1 1 2 3 x2 3 Page 5 Q19. Q20. Soaps are sodium or potassium salts of long chain carboxylic acids. Detergents are ammonium or sulphonate salts. Cleansing action of soap One part of soap molecule is ionic / hydrophilic and dissolves in water. The other part is non-ionic / carbon chain / hydrophobic part which dissolves in oil. Thus soap molecules arrange themselves in the form of a micelle / diagram of a micelle. On rinsing with water, soap is washed off, lifting the oily dirt particles with it. Soap does not form lather in hard water because of the reaction of soap with Ca and Mg ions present in hard water which forms insoluble ppt. / scum. Problems due to the use of detergents are: Detergents are non-biodegradable. It leads to water or soil pollution. It can also cause skin problems. (any two) a) Testis secrete male hormone testosterone 1 1 x2 1 Functions i) formation of sperms, ii) development of secondary sexual characters. x2 b) i) fallopian tube / /oviduct. ii) uterus. x2 Placenta is a special disc like tissue embedded in the mother s uterine wall and connected to the foetus / embryo. 1 Placenta provides a large surface area for glucose and oxygen/ nutrients to pass from the mother s blood to the embryo/ foetus. 1 Q21. a) When Mendel cross pollinated pure tall pea plants with pure dwarf pea plants, only tall plants were obtained in F1 generation. On self pollinating the F1 progeny, both tall and dwarf plants appeared in F2 generation in the ratio 3:1 Appearance of tall character in both the F1 and F2 shows that it is a dominant character. The absence of dwarf character in F1 generation and its reappearance in F2 shows dwarfness is the recessive character. b) When Mendel conducted a dihybrid cross having two sets of characters, he obtained only one set of parental characters in F1 generation whereas in F2 generation he obtained both the set of parental characters now recombined in the ratio of 9:3:3:1. The appearance of new recombinants in the F2 generation along with parental type shows that traits are inherited independently. Or Flow chart with explanation. 5 5 1 1 1 1 1 5 Q22. Power of lens:- Ability of a lens to converge or diverge the light rays falling on it/ The degree of convergence or divergence of light rays achieved by a lens/ Reciprocal of focal length of the lens. 1 dioptre It is the power of a lens whose focal length is 1 metre. f A 10 cm 0.1m Outside Delhi 31/ 1 1 Page 6 Converging/ Convex lens 1 1 PA 10D fA 0.1m f B 10 cm 0.1m Diverging/ Concave lens 1 1 PB 10D fB 0.1m In this case the object will be between the optical centre and principal focus of the lens. Hence the convex lens, i.e., lens A will form virtual and magnified image of the object. 1 Q23. Yes (Note: image must be between F2 and 2F2) u = - 15 cm v = ? h = 4 cm f = +20 cm 1 1 1 f v u 1 1 1 1 1 3 4 1 = = = v f u ( 20) ( 15) 60 60 v 60 cm Nature Virtual, erect 60 cm v ( 4 cm) 16 cm h h 15 cm u Note: Problem can be solved through ray diagram also. Q24. 5 h = ? 1 1 1 5 Ciliary muscles modify the curvature of the eye lens to enable the eye to focus objects at varying distances/ help in adjusting the focal length of the eye lens Presbyopia Bifocal lens (a) Defect Myopia/ Nearsightedness Corrective lens Concave/ Diverging lens Outside Delhi 31/ 1 1 Page 7 (b) Values Concerned, Caring etc. (one value of teacher, one value of Salman) (c) By thanking the teacher and Salman , 1 5 1x9 9 SECTION B 25) A 28) C 31) D Q34. 26) D 29) B 32) D 27) A 30) B 33) B Carbon dioxide / CO2. Lime Water turns milky when CO2 is passed through it. / CO2 extinguishes a burning splinter. Q35. Fine 1 1 2 1 1 Q36. Towards the lens Magnification decreases Outside Delhi 31/ 1 2 1 1 2 Page 8

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