Preview oswaal cbse class 10 science question bank by oswaal (2019)

Preview Oswaal cbse class 10 science question bank by Oswaal (2019) Preview Oswaal cbse class 10 science question bank by Oswaal (2019) Preview Oswaal cbse class 10 science question bank by Oswaal (2019) Preview Oswaal cbse class 10 science question bank by Oswaal (2019) Preview Oswaal cbse class 10 science question bank by Oswaal (2019)

CBSE > MARCH

2019

EXAM

CHAPTERWISE & TOPICWISE

CBSE Bock Shop, (0422) 2393093

Collegian Bock Corner, 9727297624

Unique Bock Worid, (040) 40061423

Paul Bock Depot 9988469008

Anil Paper Mart (02482) 230733

Basanta Agency, (06852) 250388

Nellore Patiala Patna

~j~

Tezpur Trivandrum Tumkur Yadodara Yallabh Vldyanagar Vijayawada Wlrdha

S.V.S Bock Centre, (0861) 2346818 Adarsh Pustalc Bhandar; (0175) 2311430 P.M Distributors, (0612.) 2303437 Royal Stationers, (0281) 2582926 Vijay Brothers, (0178) 2233959, 9418033179 Dutta Bock Stal 9402477632

Acadernic Bock House, (0471) 2333349, Palasandra promown, 9448214377 Manesh Bock Shop, 9662513447 AJay Bock Stall, (02692.) 238237 Akshaya Bock Corner, 09666155555 Unique Traders, (07152) 243617, 8600044411

The Camel Bock Depot (0863) 2320166

Himalaya Bock Worid, (040) 24732057, Sri Balaji Bock Depot

(040) 27613300 Sri Kanka Durga Bock Stall, 09849144007

Vtiayasai Bool< Centre, 9292450195 JBD Educational, 9295011552

= •hwari Bock Unk, (0891) 6661718, 9848036014

Raju Pustak Sadan, (03664) 222403, 9435120853 Bock Emporium, (0361) 2635094, Manika Bocks, 8876881519

CR Bock House, (0374) 2331191

BIHAR

New Aman Bock& Stationers, (06344) 220757, 9431612549 Pustak Bhandar 9097046555

Bokaro Student Friends, (0612) 2300600, Gvan Ganga, [0612)

2268394, Nova Publisher & Distributors, (Oli12) 2660404, 5hri Durga Pustak Mandir [0612) 2301704, Sharda Pustak Bhandar,

9204281431, Vikas Bock Depot (0612) 2304753

Chaurasia Bock Centre, 09006717044, 7004456102

CHATllSGARH

Bhagwati Bhavani Book Depot (0788) 2327620, 9827473100 Aclal'Wll Traden & Pub (0771) 6544423 4044423 7"89991679, 88785680SS, Shn Ramdev Traders, (On1)

4099445, 9425213679 DELHI

Mittal Bocks, [011) 23288887, Prozo [Global Edu4 Share Pvt

Ltx:tl, 959982M11~ 8587837835, R.D Chawla & Sens (011) 232a2361, 9,,, ,.,,,3557

GOA

~W,:~~eart Emporium, (0832) 2725208, 9370273479

~rasen Bocks & Stationel)', (0792) 7486239, Hardik Bock Agency, (079) 22148725, Pair[ Bock Agency (079) 25324741 COiiege Store, (02637) 258642

Aj!IY Bock Stalf, (02692) 238237 Aiiiam Bock Depot (112836) 237833, 9426819531 Maneesh Bock Shop, (0265) 2363270, Umakant Bock Seilers, [0265) 2359633

~~:r!~r~·~~~.~MfJl162!:1.ee:tk~

Sho~ping Point (0261) 2230~97, 9824108663,

=~r Boo~ Centre, 9825519001

~~~~~~nery, (0124) 2306991, 9899830750 Bokaro Student Friends, (0654) 2233094 Bokaro Student Friends, (0326) 2302493 Gvan Ganga Ltd (0651) 2563570, Bokaro Student Friends,

(0651) 2212447 l<ARNATAKA Tosaniwal Brothers Book Seilers, (08354) 220093 9448069493

Hema Bock Stores, (080) 41485110, Prakash Sahitva (080)

22871030, Krishna Bock & Stationers (080) 23217334 Sri Sai Ram Bock House, (080) 22111243, 9449212946

Sri Balaji Bocks & Stationers, (080) 22117659

Sapna Bock House - (Gandhinagar, (080) 40114455),

{Sadashivnagar, l080l 41236271), (la~anagar, (080) 49066700),

(Koram~n afa, (080) 40839999), (Rl!S1denJ Road, (080)

49166999 Ondiranma~40455999l, Banne'llhatta Road,( 425662 , agavara,(080)b 294151),UBS Publislier Dist 934 1469, 22266681

Chaithanya Aqencies & Bock Centre, 98B6393971

Jagdish Bock land, 9480534571

L.axmi Aqencies, (08192) 231271, 9844168836 Renuka Bock Depot (0836) 2244124, Sepna Bock House, (0836) 4249999

School Bock Co (0824) 2496938, 4281777, Sapna Bock

House, (0824) 4232800 Sapna Bock House, (0821) '4004499

Namana Bock Palace, (0816) 2277774

KERALA

Aman Bock Stall, [0495) 2721282, 9645093283 Asad Bock House, (0484) 2370431, 9447314548, Academic Bock House, (0484) 2376613, Surya Bock House, (0484)

2363721, 5u'Y!' Bock Centre, (0484) 2365149

H &C Store, (0471) 2572010, 9446411996

C Publisher : Oswaal Books

GWALlOR

!NOORE JABALPUR KATNI REWA UlJAIN AKOLA

AMRAVATI

AURANGABAD BHUSAWAL CHANDRAPUR DHULE JALGAON KOLHAPUR MUMBAI NAVIMUMBAI NAGPUR NANDED PUNE YAVATMAL BHUBANESWAR BARNALA BHATINDA LUDHIANA KDTA BHD.WARA JAIPUR COIMBAlORE CHENNA!

MADURAI

PUDUCHERRY TRICHY VILLUPURAM AGARTALA AGRA AllGARH ALLAHABAD

AZAMGARH

BALlA LUCKNOW NOIDA

VARANASI

KOLKATA SIUGURI

MADHYA PRADESH Krishna Sens, (0751) 2320431 Arun Prakashan, (0731) 2454372, 2459448, 9424890785 Akurti Publishing House, (0731) 2456024, 2456025, S.P & Sens (0731) 2452680, 2451933

Akash Bock Distributor, (0761) 4063099 Aqrasen Stationen, 9229658467, 7566414466 Slcldharth Enterprises, (07662.) 404019, 9589936626 Shree Nath Bock Depot (0734) 2556903 MAHARASlmtA

Rathi Paper Traders (0724) 2452679 Delta Pen House, (0721) 2663672 Aarti Bock Centre, (0240) 2333366, Maya Bock Cent , (0240)

2360150 Anil Bock Depot (02582) 225412, 9823446045 Novelty Bock Depot, (07172) 277418, 9422136967 Nav Jeevan Bock Stall, (0256) 2232574 Shanma Bock Depot, (0257) 6958794, 9421393040 Granth the Book Worfd, (0231) 2535355 Repro Knowledge cast Ltd, 09910403290 Sh1vam Bock & 5tationers, (022) 28381014, 28236000 Vidyarthi Sales Agencies, (022) 43029999 Krisllna Bock Store, (022) 27744962 Neel Kanth Bock House, (022) 65653535, 9930924060 Tlrupati Bock & Stationars, (0712) 2456864, L.axmi Pustakalya, (0712) 2727354, 9823098983, Renuka Bock Distributor, (0712)

~~~~~ 9765406133, Vijay Bock Depot, (0712) 2534217, Indio Bock Aqencies, 91190489460, Maheshwari General & Gift Centre, 9422870354, V(jay Bock Centre, 91172994436,

8956166999 New Venture Natr:aj Bock Shop, (020) 24485054 Sei Shubham, (020) 69498635, 9975687687 Dilip Bock Agencies, (07232) 245450, 9423131275 ODtsHA

~~~~ Bock Store, 9937617914 Bhaian Di Hatti, (01679) 232171 Janta Bock D~pot [0164) 2253993, 9872994504 Bhalla Bock centra, B8f5277131~~5807871, Chhabra Bock DeDOI !0161l 240:J<N<t, 690090, Amft Bock Depot, 9815807871

RAJASTHAN Perfect Stationery & General Shoppe, 9829863904 Raj Trader, 9309232829, 07442429090 NaKoda Bock Depot (01482) 239653, 2.43653 9214983594 Goyal Bock Distributors, (0141) 2571673

Saraswati Bock House, (0141) 2610823 TAMJLNADU

Majestic Bock House, [0422) 4384333, Sapna Bock House, (0422) 4629999

Arraba Bock Traders, (044) 25387868, 9841459105, 994061~,Ruby Bocks, C044l 26425958, Indian Bock, (044)

24327784, v1jaya S1orea, 938f037417 Jayam Book Centre, (0452) 2623636

Sn L.axmi Bock Stal~ 9443085499, Sri Saraswati Bock Stall, (04132) 222283, SALEMPattu Bock Centre, 9842428861 Rasi Publication, (0431) 2703692

Sai Kiruba Stationers, (04151) 222114 T111PURA

Bock Corner, 9856358594 UTTAR PRADESH Ajay Bock, (0562) 2254621, Manav Bock Distributor,

8126190990, 9760055997, Om Pustak Mandir, [0562.) 2464014, Panchsheel Bocks, 9412257961

Shaligram & Sens, (0571) 2421887 Mehrotra Bock Depot, (0532) 2266865 Sasta Sahitya Sadan, 9450029674 Serasweti Shishu, 8317006473, Vidya Kendra, 9415281234 Rama Bock Depot (Retail), (0522) 4080133

Goyal Bock OVersess, (0120) 383CXXXH 1, 9873387003 Global lslamic Publications, 9718474394, 9810025972 Gupta Bocks, (0542.) 2413017, 9918155500 Bofcaro Student Friends, (0542) 2401250

WESfBENGAL

Eureka Book Emporium (033) 25934001, 9051532860 Kathit-0-Kahani Pvt Ltd 22419071, 9830257999 Krishna Bock House, 8420431085, Oriental Publishers, (033)

22191591, 9830052649, Saha Bock House, (033) 22193671 Agal'Wll Bock House, (0353) 2535274 Anand Bock Point (0353) 2515953, 9002006022, Novelty Bocks, (0353) 2525445

• Mind Maps

*Note: For solutions of all the Periodic Tests, refer to the respective Topic/Chapter in the Question Bank it seif

41 - 56

In each chapter, for better understanding, questions have been classified the typology issued by CBSE as:

IBJ-Remembering, [Q] -Understanding,

CKl-Knowledge [Al -Application

2 Acids Bases and Salts 23-47 • Topic 1 Basics of Reproduction,

4 Carbon and lts Compounds 69-103 • Topic 1 Heredity and Mendel's

of Elements 104 - 130 • Topic 1 Reflection of Light,

(3)

and Electric Current

Unit V: Natural Resources

14 Sources of Energy

• Topic 1 Sources of Energy

• Topic 2 Alternative or

16 Management of Natural Resources 400 - 416

• Topic 1 Natural Resources,

Sustainable Development and Biodiversity

• Topic 2 Water Conservation

and Fossil Fuels

DD

(4)

(5)

based

We at Oswaal Books are always proactive to follow the changes proposed by the Board and implement the same as soon as possible to put the students, parents and teachers at ease The Oswaal Question Banks have been modified and rewritten as per the latest Board guidelines in order to supplement the need of the students

du ring the entire academicyear!

As the CBSE remodeled assessment structure is divided in two major parts namely Interna! Assessment and Board Examinations, Oswaal Question Banks have been designed to assist students to prepare for their periodic tests, internal assignments as weil as the Board examinations with equal ease Oswaal Question Banks will not only help students with regular studies but will also equip the teachers with the most updated study material for theclass

The Question Banks have been designed with a lot of care and attention to details All chapters are arranged 'TOPICWISE' where each topic is explained in detail and covers all typologies of Questions specified by CBSE, with weil labelled diagrams and high quality figures/diagrams for fast learning Answers from CBSE Marking scheme are highlighted in order to specify the correct method of answering questions for attaining maximum marks We hope to make Oswaal Question Banks a student's best companion to sail through the entire academic year smoothly

Same of the key highlights of Oswaal Question Banks are:

1 Chapterwise/Topicwise presentation for systematic and methodical study

2 Previous Years' Examination Questions with Marking Scheme & Toppers' Answers for exam-oriented study

3 Remembering, Understanding, Application, HOTs & Evaluation Based Question for exam-oriented preparation

4 Mind Maps in each chapterfor making learning simple

Last but not the least, we would like to offer heartfelt gratitude to our authors, editors, reviewers and specially students who regularly send us suggestions which helps in continuous improvement of this book and makes it stand out as "One of the Best" in its category

We, at Oswaal Books, wish you all a very Happy Learning and a successful 2018-19!!

-Team Oswaal

Why Topic Wise Question Banks Are A Better Choke than Previous Year' s Papers ?

1 Chapter-wise and Topic-wise presentation 1 Year Wise presentation restricts methodical

in Question Banks facilitates systematic flow of learning

study

2 Question Banks can be referred to by the 2 These can be referred to only after the students throughout the year as weil as at completion of the full syllabus in school

the completion of each chapter in school

3 Question Banks, take into account any 3 Previous Years' questions cannot be changes in syllabus or layout and hence are changed and hence fail tobe adept with the fully updated and aligned as per the latest latest Board specifications

specifications bythe Board

( 7)

Unft No Unft Marks

Note: Above weightage includes the weightage of questions based on practical skills

Unit 1: Chemical Substances • Nature and Behaviour

Chemical reactions: Chemical equation, Balanced chemical equation, implications of a balanced chemical equation, types of chemical reactions: Combination, decomposition, displacement, double displacement precipitation, neutralization, oxidation and reduction

Acids, bases and salts: Their definitions in terms of furnishing of H+ and OH- ions, General properties, examples and uses, concept of pH scale (Definition relating to logarithm not required), importance of pH in everyday life; preparation and uses of Sodium Hydroxide, Bleaching powder, Baking soda, Washing soda and Piaster of Paris

Metals and nonmetals: Properties of metals and non-metals; Reactivity series; Formation and properties of ionic compounds; Basic metallurgical processes; Corrosion and its prevention

Carbon compounds: Covalent bonding in carbon compounds Versatile nature of carbon Homologous series Nomenclature of carbon compounds containing functional groups (halogens, alcohol, ketones, aldehydes, alkanes and alkynes), difference between saturated hydrocarbons and unsaturated hydrocarbons Chemical properties of carbon compounds (combustion, oxidation, addition and substitution reaction) Ethanol and Ethanoic acid (only properties and uses), soapsand detergents

Periodic classification of elements : Need for classification, Early attempts at classification of elements (Dobereiner's Triads, Newland's Law of Octaves, Mendeleev's Periodic Table), Modem periodic table, gradation in properties, valency, atomic number, metallic and non-metallic properties

Theme: The world of the living

Unit D: World of Living

Reproduction : Reproduction in animals and plants (asexual and sexual) reproductive health-need and methods offamily planning Safe sexvs HIV/ AIDS Child bearing and women's health

Heredity and Evolution: Heredity; Mendel's contribution - Laws for inheritance of traits: Sex determination: brief introduction; Basic concepts of evolution

(9)

Refraction; Laws of refraction, refractive index

Refraction of light by spherical lens; Image formed by spherical lenses; Lens formula (Derivation not required); Magnification Powerof a lens

Functioning of a lens in human eye, defects of vision and their corrections, applications of spherical mirrors and lenses

Refraction of light through a prism, dispersion of light, scattering of light applications in daily life

Theme: HowThings Work

Unit IV: Effects of Current

(32 Periods)

Electric current, potential difference and electric current Ohm's law; Resistance, resistivity, Factors on which the resistane of a conductor depends Series combination of resistors, parallel combination of resistors and its applications in daily life Heating effect of electric current and its applications in daily life Electric power,

Magnetic effects of current: Magnetic field, field lines, field due to a current carrying conductor, field due to current carrying coil or solenoid; Force on current carrying conductor, Fleming's Left Hand Rule, Electric Motor, Electromagnetic induction lnduced potential difference, lnduced current Fleming's Right Hand Rule, Electric Generator, Direct Current Alternating current: frequency of AC Advantage of AC over DC Domestic electric circuits

Theme: Natural Resources

Unit V: Natural Resources

(20 Periods)

Sources of energy: Different forms of energy, conventional and non-conventional sources of energy: Fossil fuels, solar energy; biogas; wind, water and tidal energy; Nuclear energy Renewable versus non-renewable sources of Energy

Our environment : Eco-system, Environmental problems, Ozone depletion, waste production and their solutions Biodegradable and non-biodegradable substances

Management of natural resources: Conservation and judicious use of natural resources Forest and wild life; Coal and Petroleum conservation Examples of people's participation for conservation of natural resources Big dams: advantages and limitations; alternatives, if any Water harvesting Sustainability of natural resources

PRACTICALS LAB WORK

Pradical should be conducted alongside the concepts taught in theory classes

UST OF EXPERIMENTS

c Dilute Ethanoic Acid solution

( 11 )

PAPER 2018

Class–X Delhi/Outside Delhi Set

Science

General Instructions :

(iii) All questions of Section A and Section B are to be attempted separately.

answered in brief.

SECTION – A

1 A Mendelian experiment consisted of breeding pea plants bearing violet flowers with pea plants bearing white

flowers What will be the result in F1 progeny ?

2 Write the energy conversion that takes place in hydropower plant.

3 A compound ’X’ on heating with excess conc sulphuric acid at 443 K gives an unsaturated compound ‘Y’, ‘X’ also

reacts with sodium metal to evolve a colourless gas ‘Z‘ Identify ‘X’, ‘Y’ and ‘Z’ Write the equation of the chemical reaction of formation of ‘Y’ and also write the role of sulphuric acid in the reaction.

4 (a) Name one gustatory receptor and one olfactory receptor present in human beings.

(b) Write a and b in the given flow chart of neuron through which information travels and as an electrical impulse.

5 If the image formed by a spherical mirror for all position of the object placed in front of it is always erect and

diminished, what type of mirror is it ? Draw a labelled ray diagram to support your answer

6 Decomposition reactions required energy either in the form of heat or light or electricity for breaking down the

reactants Write one equation each for decomposition reactions where energy is supplied in the form of heat, light and electricity

7 2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube When the

contents are warmed, a gas evolves which is bubbled through a soap solution before testing Write the equation of the chemical reaction involved and the test to detect the gas Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid

OR The pH of a salt used to make tasty and crispy pakoras is 14 Identify the salt and write a chemical equation for its formation List its two uses

8 (a) Why are most carbon compounds poor conductors of electricity ?

(b) Write the name and structure of a saturated compound in which the carbon atoms are arranged in a ring Give

the number of single bonds present in this compound

9 Name the hormones secreted by the following endocrine glands and specify one function of each :

10 Write one main difference between asexual and sexual mode of reproduction Which species is likely to have

comparatively better chances of survival — the one reproducing asexually or the one reproducing sexually ? Give reason to justify your answer

What is meant by power of a lens ? Write the SI unit A student uses a lens of focal length 40 cm and another of – 20 cm Write the nature and power of each lens.

12 Show how would you join three resistors, each of resistance 9 W so that the equivalent resistance of the

combination is (i) 13.5 W, (ii) 6 W ?

OR (a) Write Joule's law of heating

(b) Two lamps one rated 100 W; 220 V, and the other 60 W; 220 V, are connected in parallel to electric mains supply

Find the current drawn by two bulbs from the line, if the supply voltage is 220 V

13 (a) List the factors on which the resistance of a conductor in the shape of a wire depends.

(b) Why are metals good conductors of electricity whereas glass is a bad conductor of electricity ? Give reason

(c) Why are alloys commonly used in electrical heating devices ? Give reason

14 Students in a school listened to the news read in the morning assembly that the mountain of garbage in Delhi,

suddenly exploded and various vehicles got buried under it Several people were also injured and there was traffic jam all around In the brain storming session the teacher also discussed this issue and asked the students

to find out a solution to the problem of garbage Finally they arrived at two main points – one is self management

of the garbage we produce and the second is to generate less garbage at individual level

(a) Suggest two measures to manage the garbage we produce

(b) As an individual, what can we do to generate the least garbage ? Give two points

(c) List two values the teacher instilled in his students in this episode

15 What is dam ? Why do we seek to build large dams ? While building large dams, which three main problems

should particularly be addressed to maintain peace among local people ? Mention them

16 (a) Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate

ores

(b) How is copper extracted from its sulphide ore ? Explain the various steps supported by chemical equations

Draw labelled diagram for the electrolytic refining of copper

17 (a) The modern periodic table has been evolved through the early attempts of Dobereiner, Newland and

Mendeleev List one advantages and one limitation of all the three attempts

(c) Name the scientist who first of all showed that atomic number of an element is a more fundamental property

than its atomic mass

(c) State Modern periodic law

18 (a) Mention any two components of blood.

(b) Trace the movement of oxygenated blood in the body

(c) Write the function of valves present in between atria and ventricles

(d) Write the structural difference between the composition of artery and veins

OR (a) Define excretion

(b) Name the basic filtration unit present in the kidney

(c) Draw excretory system in human beings and label the following organs of excretory system which perform

following functions :

(i) form urine

(ii) is a long tube which collects urine from kidney

(iii) store urine until it is passed out

19 (a) Write the function of following parts in human female reproduction system :

(b) Describe in brief the structure and function of placenta

20 (a) A student is unable to see clearly the words written on the black board placed at a distance of approximately

3 m from him Name the defect of vision the boy is suffering from State the possible causes of this defect and explain the method of correcting it

(b) Why do stars twinkle ? Explain

OR (a) Write the function of each of the following parts of human eye :

(b) Why does the sun appear reddish early in the morning ? Will this phenomenon be observed by an astronaut

on the Moon ? Give reason to justify your answer

21 (a) State Fleming's left and rule.

(b) Write the principle of working of an electric motor

(c) Explain the function of the following parts of an electric motor

(a) Identify and state the feature of the concept discussed in the above paragraph.

(b) Also, state any four points of importance of this concept.

22 A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron

sulphate and copper sulphate In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate

In which test tube or test tubes will she observe colour change ? On the basis of this experiment, state which one

is the most reactive metal and why

23 What is observed when a solution of sodium sulphate is added to a solution of barium chloride taken in a test tube ?

Write equation for the chemical reaction involved and name the type of reaction in this case

24 List the steps of preparation of temporary mount of a leaf peel to observe stomata.

25 Name the process by which an amoeba reproduces Draw the various stages of its reproduction in a proper

sequence

OR

A student is viewing under a microscope a permanent slide showing various stages of asexual reproduction by budding in yeast Draw diagrams of what he observes (in proper sequence)

26 An object of height 4.0 cm is placed at a distance of 30 cm from the optical centre ’O’ of a convex lens of focal

length 20 cm Draw a ray diagram to find the position and size of the image formed Mark optical centre ‘O’ and principal focus ‘F’ on the diagram Also find the approximate ratio of size of the image to the size of the object

27 The values of current (I) flowing through a given resistor of resistance (R), for the corresponding values of

potential difference (V) across the resistor are as given below :

2 Potential Energy (stored water in dam) → Kinetic Energy (water falling from dam on turbine) → Electrical

3 Compound X is Ethanol, Y is Ethene and Z is Hydrogen gas.

CH3CH2OH H SO443K

2 4

→ CH2 = CH2 + H2O Concentrated sulphuric acid acts as dehydrating agent in this reaction and removes a molecule of water.

When Ethanol (x) reacts with sodium colourless Hydrogen gas (z) is evolved.

4 (a) The gustatory receptor is the tongue and olfactory receptor is nose.

5 A Convex mirror forms an erect diminished virtual image for all position's of the object placed in front of it 1+1

6 (i) Thermal Decomposition

(ii) Photochemical Decomposition

(Water) (Hydrogen) (Oxyen) 1+1+1

7 When sodium hydroxide is heated with Zinc granules – Sodium Zincate and hydrogen gas is evolved.

When burning splinter is brought near the mouth of the test tube, it burns with a pop sound

If Zinc granules reacts with strong acids (HCl or H2SO4) then again Hydrogen gas will be evolved

OR The salt is Baking Soda i.e., Sodium bi carbonate

Uses of Baking Soda

(i) It is used as an antacid as it reduces the acidity in the stomach

(ii) Due to the formation of soapy foam, it is used in fire extinguishers 1+1+1

8 (a) Carbon compounds are poor conductors of electricity as they form covalent bond and thus so it does not give

rise to free electrons or ions in aqueous solution

(b) Cycloalkanes are the group of saturated compounds in ring e.g., Cyclopropane

9 (a) The hormone secreted by thyroid gland is thyroxine It regulates carbohydrate, protein and fat metabolism

in the body so as to provide the best balance for growth

(b) Pituitary gland secretes growth hormone It regulates growth and development of the body

(c) Pancreas secretes hormone insulin It helps in regulating the blood sugar level 1+1+1

10 Asexual Reproduction involves only one parent and offsprings are identical.

Sexual Reproduction involves two parents and genetic variation occurs in the offsprings

Sexually reproducing species have a better chance of survival because their variations developed during reproduction enables the newer offsprings to survive the changes in environment It allows the formation of new variants by the combination of the DNA from two different individuals, typically one of each sex 1+1+1

11 Laws of Refraction

(i) The incident ray, the refracted ray and the normal to the transparent surface at the point of incidence all lie

in the same plane

(ii) The ratio of the sine of angle of incidence in the first medium to the sine of angle of refraction in the second

medium is a constant for a given pair of medium and for a given wavelength of light

Absolute refractive index of a medium is defined as the ratio of the speed of light in vaccum or air to the speed

of light in the medium It is denoted by n.

n = speed of light in medium ( )speed of light in air ( )c v 1+1+1

OR The reciprocal of focal length of a lens is termed as power of a lens

SI unit of power is Dioptre

Focal length + 40 cm of a lens tells that it is convex lens as its focal length is in positive = p = 1 100f = 40 = +2.5 D

Focal length – 20 cm tells that it is concave lens = p = 1 100f = 20

2

+ = 1 2

18

+ = 318

(a) Joule's Law of Heating states that the heat produced in a conductor is directly proportional to (i) the square

of the current I through it (ii) its resistance R and (iii) the time t, for which current is passed.

(b) Power of one lamp = 100 W

Power of second lamp = 60 W

Total power consumed in the circuit = 100 + 60 = 160 W

Voltage of the main supply = 220 V

13 (a) The factors on which the resistance of a conductor in the shape of a wire depends are :

Thickness (cross sectional area of the wire), length, temperature and conductivity of the material that is used (b) Metal particles are held together by strong metallic bonds, and they have high melting and boiling points The free electrons in metals can move through the metal, allowing metals to conduct electricity Whereas glass does not have free electrons to conduct free electrons resulting as bad conductors of electricity

(c) Alloys are used rather than pure metals in electrical heating devices since they have low electrical conductivity and low melting point Alloys also have higher resistivity than metals

14 (a) Two measures to manage the garbage we produce are :

(i) Reduce the use of non-biodegradable waste like plastic bags

(i) Recycling

(b) (i) Use jute or cloth bags

(ii) Green leafy wastes can be decomposed as manure

(c) Values shown by teacher is awareness towards environment protection and knowledge of subject 1+1+1

15 A dam is a barrier that stops or restricts the flow of water or underground streams.

A dam is built to control water through placement of a blockage of earth, rock across a stream or river They usually store water in a reservior, which is then used for a variety of applications such as irrigation and municipal water supplies

Three main problems that arise because of the construction of big dams are :

(i) Construction of dams across rivers leads to deforestation, which results in the loss of biodiversity

(ii) Constructing reservoir may result in the flooding of nearby towns and villages

(iii) Construction of dams requires a huge amount of monetary investments 1½+1½

16 (a) A metal is obtained from its carbonate ore by converting it into its oxide by the process of Calcination.

In Calcination, the ore is heated to a high temperature in the absence of air

carbon, aluminium which depend upon the reactivity of the metal.

Impure Zn obtained is refined by electrolysis process

(b) In the extraction of copper from its Sulphide Ore, when ore is subjected to roasting, some of it is oxidised to Cu2O

which reacts with the remaining Cu2S to give copper metal In this process, Cu2S behaves as reducing agent

In electrolytic refining of copper, the impurities left behind at anode called anode mud contains valuable

metals such as gold and silver which can be recovered in the native state

+

Cathode(Pure metal)

Solution ofmetal salt(Electrolyte)

Anode(Impuremetal)Anode mud

Electrolytic refining

17 (a)

Dobereiner Properties of elements in each triad were

similar Only three triads were identified Triads for all known elements were not prepared.Newland The properties of the first element is similar

to the eighth element It was only applicable upto Calcium Rest of the elements were not discovered.Mendeleev It was easy to study the physical and chemi-

cal properties of various elements Position of hydrogen was not assign Position of Isotopes were not certain

(b) Henry Moseley

(c) Modern Periodic Law : Physical and chemical properties of elements are the periodic functions of their

18 (a) Two components of Blood are — Plasma and Blood Corpuscles.

(b) Oxygenated blood arrives at the right hand side of the heart It enters the heart through the pulmonary vein Blood is pumped into the left ventricle Blood is pumped out of the heart, along the aorta, to the rest of the body (c) As the heart muscle contracts and relaxes, the valves open and shut, letting blood flow into the ventricles and atria at alternate times When the left ventricle contracts, the mitral valve closes and the aortic valve opens,

so blood flows into the aorta

(d) Artery wall is thick and valves are absent whereas vein wall is thin and valve are present 1+2+1+1

(b) Placenta is a special tissue that helps human embryo in obtaining nutrition from mother's blood.

tissue, and on the mother's side are blood spaces which surround the villi

of CO2 from the foetus It is also involved in removal of wastes generated by embryo through the placenta

20 (a) The defect is Myopia or short-sightedness i.e., Inability of an eye in viewing long distance objects This defect

is caused by an elongation of eye-ball and excessive curvature of the lens

The short-sightedness is corrected by using a concave lens which diverges and shifts the image to the retina

Parallel rays coming from

IimageRetina

RetinaParallel rays coming

from distant objectF

Virtual imageformed at F

L

(b) Stars are very distant and approximately point-sized sources Path of star light changes continuously due to

gradual changing of refractive index of the layers of earth's atmosphere Thus, the apparent position of the stars fluctuates and the amount of star light entering the eye flickers giving the twinkling effect 3+2

OR (a) (i) Cornea : If refracts most of the light into eyes.

(b) Early in the morning, the sun is near the horizon, sunlight reaches us after travelling a longer distance through

thick layers of atmosphere Thus, most of the blue light and shorter wavelength are scattered away by the particles in the atmosphere The light that reaches us is of longer wavelengths giving a reddish appearance

This phenomenon will not be observed by an astronaut on the moon, because of the absence of atmosphere

21 (a) Fleming's Left Hand Rule :

Fleming's Left Hand Rule : Stretch the first three fingers of the left hand mutually perpendicular to each

other such that the forefinger points the direction of magnetic field, the middle finger points the direction of current, then the thumb will indicate the direction of force experienced by the conductor

(b) Electric motor works on the principle of force experienced by a current carrying conductor in a magnetic

field The two forces in the opposite sides are equal and opposite

(c) (i) Armature : It is a rectangular iron core wrapped by copper coil through which electricity passes and due

to magnetic field it experiences a force and rotates

shaft

SECTION – B

22 When aluminium is added to test tubes A and B containing aqueous solutions of iron sulphate and copper

sulphate, aluminium will displace both iron and copper from their salt solutions as aluminium is more reactive than both iron and copper Also, iron when added to test tube C containing aluminium sulphate will not react but will displace copper from its salt solution in test tube D Hence, the colour change will take place in test tubes

A, B and D and no colour will take place in C Aluminium is the most reactive metal of all as it can displace both

A white precipitate of barium sulphate insoluble in water is observed It is a double displacement reaction 1+1

24 (i) The leaf peel of lower epidermis is taken and cut with a blade.

(ii) The cut pieces are transferred into a petridish containing water

(vi) Remove the excess stain and glycerin with the help of blotting paper.

25 Amoeba reproduces by binary fission.

− = 3 2

60

− = 160

h h

′

= v u = h′=

−4

ll

(Issued by

Outside Delhi Set-I

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 (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.

Outside Delhi Set-I Code No 31/1

4 An object is placed at a distance of 30 cm from a concave lens of focal length 15 cm List four characteristics

(nature, position, etc.) of the image formed by the lens 2

Ans.

Write the chemical equation for the reaction stating the role of conc H2SO4 in this reaction 3

Ans.

9 Write the number of periods and groups in the Modern Periodic Table How does the metallic character of elements

vary on moving (i) from left to right in a period, and (ii) down a group ? Give reason to justify your answer 3

Ans.

respectively Which one of these elements has the (a) highest valency, (b) largest atomic radius, and (c) maximum

chemical reactivity ? Justify your answer stating the reason for each 3

Ans.

13 List three techniques that have been developed to prevent pregnancy Which one of these techniques is not

meant for males ? How does the use of these techniques have a direct impact on the health and prosperity of a

family ? 3

14 How did Mendel explain that it is possible that a trait is inherited but not expressed in an organism ? 3 Ans.

15 "Evolution and classification of organisms are interlinked." Give reasons to justify this statement 3 Ans.

16 If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished, what

is the nature of this lens ? Draw a ray diagram to justify your answer If the numerical value of the power of this

lens of 10 D, what is its focal length in the Cartesian system ? 3

Ans.

17 State the cause of dispersion of white light by a glass prism How did Newton, using two identical glass prisms,

show that white light is made of seven colours ? Draw a ray diagram to show the path of a narrow beam of white light, through a combination of two identical prisms arranged together in inverted position with respect to each

other, when it is allowed to fall obliquely on one of the faces of the first prism of the combination 3

Ans.

a formative assessment activity, "How to save water, the vital natural resource" Write any two ways that you will suggest to bring awareness in your neighbourhood, on 'how to save water'

(b) Name and explain any one way by which the underground water table does not go down further 3

Ans.

19 Why are certain compounds called hydrocarbons ? Write the general formula for homologous series of alkanes,

alkenes and alkynes and also draw the structure of the first member of each series Write the name of the reaction that converts alkenes into alkanes and also write a chemical equation to show the necessary conditions for the

(iii) Fallopian tube

Ans.

21 With the help of one example for each, distinguish between the acquired traits and the inherited traits Why are

the traits/experiences acquired during the entire lifetime of an individual not inherited in the next generation ?

Explain the reason of this fact with an example 5

Ans.

22 Analyse the following observation table showing variation of image-distance (v) with object-distance (u) in case

of a convex lens and answer the questions that follow without doing any calculations : 5

6 – 15 + 120

(a) What is the focal length of the convex lens ? Give reason to justify your answer.

(b) Write the serial number of the observation which is not correct On what basis have you arrived at this

conclusion ?

(c) Select an appropriate scale and draw a ray diagram for the observation at S.No.2 Also find the approximate

value of magnification

Ans.

and virtual, state the type of the mirror and also draw a ray diagram to justify your answer Write one use such mirrors are put to and why

(b) Define the radius of curvature of spherical mirrors Find the nature and focal length of a spherical mirror

whose radius of curvature is + 24 cm 5

24 (a) A student suffering from myopia is not able to see distinctly the objects placed beyond 5 m List two

possible reasons due to which this defect of vision may have arisen With the help of ray diagrams, explain

(i) Why the student is unable to see distinctly the objects placed beyond 5 m from his eyes

(ii) The type of the corrective lens used to restore proper vision and how this defect is corrected by the use

of this lens

(b) If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the lens

as per the new Cartesian sign convention 5

Ans.

SECTION B

following is your observation ? 1

(a) No reaction takes place

(b) A colourless gas with pungent smell is released with brisk effervescence

(c) A brown coloured gas is released with brisk effervescence

(d) Formation of bubbles of a colourless and odourless gas

Ans.

vegetable oil and 20% aqueous solution of NaOH in a beaker ? 1

(a) The colour of the mixture has become dark brown

(b) A brisk effervescence is taking place in the beaker

(c) The outer surface of the beaker has become hot

(d) The outer surface of the beaker has become cold

Ans.

In the laboratory there are some salts, which when dissolved in distilled water can convert it into hard water Select from the following groups of salts, a group, each salt of which when dissolved in distilled water will make

it hard 1

(a) Sodium chloride, Potassium chloride

(b) Sodium sulphate, Potassium sulphate

(c) Sodium sulphate, Calcium sulphate

(d) Calcium sulphate, Calcium chloride

Ans.

(a) Wheat, Gram and Pea

(b) Gram, Pea and Ground-nut

(c) Maize, Pea and Barley

(d) Gram, Maize and Ground-nut

Ans.

Potato, Tomato, Radish, Brinjal, Carrot, Bottle-gourd Which two of these vegetables correctly represent the homologous structures ?

(a) Carrot and Tomato

(b) Potato and Brinjal

(c) Radish and Carrot

(d) Radish and Bottle-gourd

(a) Device X is a concave mirror and device Y is a convex lens, whose focal lengths are 20 cm and 25 cm respectively

(b) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 10 cm and 25 cm

respectively

(c) Device X is a concave lens and device Y is a convex mirror, whose focal lengths are 20 cm and 25 cm respectively

(d) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 20 cm and 25 cm respectively

Ans.

on the screen he should move the lens 1

(a) away from the screen

(b) towards the screen

(c) to a position very far away from the screen

(d) either towards or away from the screen depending upon the position of the object

Ans.

(a) Ði > Ðr > Ðe (b) Ði = Ðe > Ðr

determining the nature (acidic/alkaline) of the reaction mixture of saponification reaction 2

Ans.

Ans.

screen After that he moves gradually the flame towards the lens and each time focuses its image on the screen

2 (i) In which direction does he move the lens to focus the flame on the screen ?

(ii) What happens to the size of the image of the flame formed on the screen ?

(iii) What difference is seen in the intensity (brightness) of the image of the flame on the screen ?

(iv) What is seen on the screen when the flame is very close (at about 5 cm) to the lens ?



Pre-Mid Term Tests

Chemistry-1,2, Physics-10,11, Biology-6,7

Note : (For solution of all the periodic tests, refer to the respective Topic/Chapter in the Question Bank itself.)

a When bleaching powder is kept open in air.

Mid Term Tests

Chemistry-1,2,3,4 Physics-10,11,12,13 Biology-6,7,8 & 9

Post-Mid Term Tests

Chemistry-1,2,3,4,5 Physics-10,11,12,13 and 14

Biology-6,7,8, 9,15 and 16

a Rusting of iron