Category: Class 10

BIOLOGY 

SCIENCE Paper – 3 

SECTION -I  

Attempt all questions from this Section  

Q.1 (a) Name the following: 

          (i) The layer of the eyeball that provides nourishment to the eye. 

          (ii) One gaseous compound which depletes the ozone layer. 

          (iii) The structure which connects the placenta and the foetus. 

          (iv) A pair of corresponding chromosomes of the same shape and size and  derived one from each parent. 

          (v) The compound formed when haemoglobin combines with carbon dioxide  in blood.

(b) Correct and rewrite the statements by changing the biological term that is  underlined for each statement: 

          (i) The theory of Inheritance of Acquired Characters was proposed by Watson  and Crick. 

          (ii) The protective sac which develops around the developing embryo is called  the Pericardium. 

          (iii) Maintaining balance of the body and coordinating muscular activities is  carried out by the cerebrum. 

          (iv) The kidney is composed of number of neurons. 

          (v) The part of the eye which can be donated from a clinically dead person is the Retina. 

(c) Give suitable biological reasons for the following statements: 

          (i) The birth rate in India is very high. 

          (ii) Carbon monoxide is dangerous when inhaled. 

          (iii) Root hairs become flaccid and droop when excess fertilizers are added to  the moist soil around them. 

          (iv) Acid rain is harmful to the environment. 

          (v) All life on Earth is supported by Photosynthesis. 

(d) Match the items given in Column A with the most appropriate ones in Column B and REWRITE the correct matching pairs: 

Column A	Column B
(i) Cranial nerves (ii) Leydig cells (iii) Acetylcholine (iv) Spinal nerves (v) Sneezing	– Testosterone  – Natural reflex  – 12 pairs  – Prolactin  – Neurotransmitter  – 18 pairs  – 31 pairs  – Conditioned reflex

(e) Choose the correct answer from the four options given below: 

          (i) While recording the pulse rate, where exactly does a doctor press on our  wrist? 

          A. Nerve  

          B. Vein 

          C. Artery  

          D. Capillary 

          (ii) In a human male, a sperm will contain: 

          A. Both X and Y chromosomes  

          B. Only Y chromosome 

          C. Only X chromosome  

          D. Either X or Y chromosome 

          (iii) A muscular wall is absent in: 

          A. Capillary 

          B. Venule 

          C. Arteriole 

          D. Vein 

          (iv) On which day of the menstrual cycle does ovulation take place? 

          A. 5^th day 

          B. 28^th day 

          C. 14^th day 

          D. 1^st day 

          (v) Which one of the following does not affect the rate of transpiration? 

          A. Light  

          B. Humidity 

          C. Wind  

          D. Age of the plant 

(f) Identify the ODD term in each set and name the CATEGORY to which the remaining three belong:  

          Example: glucose, starch, cellulose, calcium 

        Odd term: calcium  

        Category: others are different types of carbohydrates. 

          (i) Addison’s disease, Cushing’s Syndrome, Acromegaly, Leukemia. (ii) Insulin, Adrenaline, Pepsin, Thyroxine. 

          (iii) Axon, Dendron, Photon, Cyton. 

          (iv) Chicken pox, Colour blindness, Haemophilia, Albinism. 

          (v) Polythene bag, Crop residue, Animal waste, Decaying vegetable.

(g) Expand the following biological abbreviations: 

          (i) ABA 

          (ii) IAA 

          (iii) ATP 

          (iv) DNA 

          (v) TSH 

(h) Study the picture given below and answer the following questions: 

          (i) Identify the type of pollution. 

          (ii) Name one pollutant that causes the above pollution. 

          (iii)Mention the impact of this pollution on human health. 

          (iv) State one measure to control this pollution. 

          (v) What is a ‘Pollutant’? Explain the term. 

Answer:

(a) (i) Choroid

      (ii) Chlorofluorocarbon (CFC) or carbon tetrachloride

      (iii) Umbilical cord

      (iv) Homologous chromosomes

      (v) Carbaminohaemoglobin/HbCO₂

(b) (i) Jean-Baptiste Lamarck

      (ii) Amnion

     (iii) Cerebellum

     (iv) Nephrons/ Uriniferous tubules

     (v) Cornea

(c) (i) Illiteracy, children are a gift of God, sign of prosperity, due to high infant mortality, more helping hands for family income, do not accept family planning methods, desire for a male child, lack of recreation.

     (ii) Easily combines with haemoglobin to form carboxyhaemoglobin which cuts off supply of oxygen to tissues.

     (iii) Formation of hypertonic solution which results in plasmolysis / exosmosis.

      (iv) Pollutes soil, damages vegetation, buildings, statues, monuments, kills fish and aquatic animals.

       (v) All organisms depend directly or indirectly on green plants for food, beginning of all food chains, provides oxygen for respiration.

(d)

(e) (i) C. Artery

      (ii) D. Either X or Y chromosome

      (iii) A. Capillary

      (iv) C. 14th day

      (v) D. Age of the plant

(f) (i) O – Leukemia

C – Hormonal / Endocrinal disorders

     (ii) O – Pepsin

C – Hormones

     (iii) O – Photon

C – Parts of neuron / nerve cell

     (iv) O – Chicken pox

C – Genetic diseases

     (v) O – Polythene bag

C – Biodegradable wastes

(g) (i) Abscisic acid

      (ii) Indole 3-acetic acid

      (iii) Adenosine triphosphate

      (iv) Deoxyribo nucleic acid

      (v) Thyroid stimulating hormone

(h) (i) Water pollution/ Marine pollution

      (ii) Detergents, sewage, domestic waste, oil spills from tankers, industrial wastes, hot water from thermal power plants, polythene covers, plastic bottles, dead bodies, insecticides, etc.

       (iii) Enters food chain to harm health, cause diseases like typhoid, dysentery, jaundice, skin allergies, etc.

       (iv) Treating industrial wastes and sewage before letting into water bodies, recycling plastic, metal and glass material

       (v) Any constituent that harms the environment / deteriorates the natural quality of air, water, soil.

 

SECTION II (40 Marks) 

Attempt any four questions from this Section. 

Q.2 (a) Given below is an experimental setup to demonstrate a particular tropic movement in germinating seeds. Study the diagram and answer the questions that follow: 

(i) Label the parts 1 and 2. 

(ii) Name the tropic movement shown by part 1. 

(iii) Part 1 is affected by two stimuli. Name them. Which one of the two is stronger? 

(iv) What is Thigmotropism? Give one example. 

(v) What is meant by ‘Positive’ and ‘Negative’ tropic movements in plants?

(b) Mention the exact location of the following: 

          (i) Testis 

          (ii) Incus 

          (iii) Thylakoids 

          (iv) Amniotic fluid 

          (v) Corpus callosum 

Answer:

(a) (i)

• Radicle
• Plumule

(ii) Hydrotropism

(iii) Gravity, water / moisture

Water is stronger

(iv) Movement of plant in response to touch stimulus.

Pea, Vines, Cuscuta, cucumber

(v) Movement towards stimulus is positive.

Movement away from stimulus is negative.

(b) (i) Inside scrotal sac

(ii) Middle ear / between malleus and stapes

(iii) In chloroplast

(iv) Between amnion and foetus / surrounds the foetus

(v) Between the cerebral hemispheres.

Q.3 (a) The diagram given below represents an experiment to prove the importance of  a factor in photosynthesis. Answer the questions that follow: 

          (i) Name the factor studied in this experiment. 

          (ii) What will you observe in the experimental leaf after the starch test?  

          (iii) Explain the process of Photosynthesis. 

          (iv) Give a balanced chemical equation to represent the process of  photosynthesis. 

          (v) Draw a neat, labelled diagram of an experimental setup to show that  oxygen is released during photosynthesis. 

(b) State the main functions of the following: 

          (i) Medulla Oblongata 

          (ii) Cytokinins 

          (iii) Tears 

          (iv) Coronary Artery 

          (v) Seminal Vesicles 

Answer:

(a) (i) Sunlight

       (ii)  – Part of leaf covered by black paper turns brown, absence of starch.

              – Parts of leaf exposed to sunlight turns blue black, presence of starch.

       (iii) Plant cells having chlorophyll, use water and carbon dioxide to produce glucose in the presence of sunlight.

       

(b) (i) Regulates activities of internal organs like breathing, heartbeat, peristalsis.

        (ii) Stimulates cell division, plant growth, prevents ageing,expansion of cotyledons in seeds,breaks seed dormancy, promotes synthesis of chloroplasts, delays senescence.

       (iii) Lubricates surface of eye, washes away dust, kill germs, keeps surface of eye moist, lysozyme kills bacteria.

       (iv) Supplies oxygenated blood to the walls of the heart.

        (v) Activates sperms, forms a medium for transportation of sperms.

 

Q.4 (a) The diagram given below represents an organ system in the human body.  

Study the same and answer the questions that follow: 

          (i) Identify the system. 

          (ii) Label the parts marked 2 and 4. Mention the function of part 5. 

          (iii) Name the structural and functional units of the part marked 1. 

          (iv) What is the fluid that accumulates in part 3? Which is the main nitrogenous waste present in it? 

          (v) Draw a neat, labelled diagram showing the longitudinal section of part 1. 

(b) The diagram given below represents an endocrine gland in the human body.  

Study the diagram and answer the following questions: 

          (i) Identify the endocrine gland. Where is it located? 

          (ii) Why is the above gland referred to as the ‘Master gland’? 

          (iii) Name the hormone which in deficiency causes Diabetes Insipidus. 

                 How does this disorder differ from Diabetes Mellitus? 

          (iv) Explain the term ‘Hormone’. What is the role of Tropic hormones in the human body? 

          (v) Which lobe of the above gland secretes: 

                  1. Oxytocin 

                  2. ACTH 

                  3. Growth hormone 

Answer:

(a) (i) Excretory system/Urinary system

      (ii) 2 – Ureter

            4 – Sphincter

             5 – Expels urine

(iii) Nephrons

(iv) Urine, Urea

(v) 

(b) (i) Pituitary gland

             Hangs from hypothalamus

(ii) Controls the secretions of other endocrine glands/regulates the activities of other endocrine glands.

(iii) Vasopressin / ADH

        Diabetes mellitus is due to deficiency of insulin/ high level of sugar in blood, urine has sugar.

        Diabetes insipidus: Normal sugar in blood, urine free of sugar / urine loaded with water.

(iv) It is the secretion of an endocrine gland, which is transported by blood and acts on target organs or cells.

       Secreted by pituitary gland and stimulates other endocrine glands to secrete their hormones.

(v) 1 – Posterior/ neurohypophysis

      2 – Anterior / adenohypophysis

      3 – Anterior /adenohypophysis

Q.5 (a) Given below is an apparatus which was setup to investigate a physiological process in plants. The setup was placed in bright sunlight. Answer the questions that follow: 

(i) Name the process being studied. Define the process. 

(ii) Why was the pot enclosed in a rubber sheet? 

(iii) Mention two external factors which can accelerate the above process. 

(iv) List two adaptations in plants to reduce the above process. 

(v) Draw a neat, labelled diagram of a stomatal apparatus. 

(b) Given below are two stages in the evolution of man.  

Study them and answer the questions that follow: 

(i) Identify Australopithecus and Neanderthal man from the above pictures. 

(ii) Mention two characteristic features each for the two stages. 

(iii) Who proposed the theory of ‘Natural Selection’? 

(iv) Name the organism used as an example to explain ‘Industrial Melanism’. 

(v) Give two examples of Vestigial organs in humans. 

Answer:

(a) (i) Transpiration

It is the loss of water as water vapour from the aerial parts of the plant.

(ii) To prevent evaporation of water from the pot/ soil.

(iii) Bright sunlight, high temperature, high velocity of wind, low humidity.

(iv) Thick cuticle, loss of leaves, narrow leaves, fewer stomata, sunken stomata, leaves modified into spines, multiple layers of epidermal cells.

(v)

(b) (i) A – Neanderthal man

B – Australopithecus

(ii) A – absolute bipedalism, large head, broad, flat, sloping forehead, less hair on body, large cranial capacity 1,500 cm3,

B – Protruding face, Chin absent, prominent eyebrow ridges, flat nose, projecting face, cranial capacity (450- 600 cm3).

(iii) Charles Darwin

(iv) Peppered moth / Biston betularia

(v) Pinna of ear, wisdom teeth, vermiform appendix, coccyx or tailbone, arrector pili, plica semilunaris, body hair, male nipples.

Q.6 (a) In Mendel’s experiments, tall pea plants (T) are dominant over dwarf pea plants (t).  

(i) What is the phenotype and genotype of the F1 generation if a homozygous  tall plant is crossed with a homozygous dwarf plant? 

(ii) Draw a Punnett square board to show the gametes and offspring when both  the parents are heterozygous for tallness. 

(iii) What is the phenotypic ratio and genotypic ratio of the above cross in (ii)? 

(iv) State Mendel’s Law of Dominance. 

(v) What is a Dihybrid Cross? 

(b) Given below is a diagram representing a stage during the mitotic cell division.  

Study the diagram and answer the following questions: 

(i) Identify the stage by giving a suitable reason. 

(ii) Is it a plant or an animal cell? Give a reason to support your answer. 

(iii) Draw a neat, labelled diagram of the stage which follows the one shown in  the diagram. 

(iv) How many chromosomes will each daughter cell have after the completion  of the above division? 

(v) Name the four nitrogenous bases. 

Answer : (a) (i) Phenotype – all are tall plants

Genotype – All are hybrid / heterozygous dominant

(iii) Phenotypic ratio – 3 : 1

Genotypic ratio – 1 : 2 : 1

(iv) Out of a pair of contrasting characters, the one that is expressed is dominant and the one that is not expressed is recessive.

(v) It is breeding plants taking two pairs of contrasting characters.

(b) (i) Anaphase

Chromatids are being pulled towards the opposite poles.

(ii) Animal cell

Cell wall is absent, centrioles are present, asters are present.

(iii)

(iv) 4

(v) Adenine, Thymine, Cytosine, Guanine.

 

Q.7 (a) Answer the following questions briefly: 

(i) How are the cytons and axons placed in the brain and the spinal cord? 

(ii) Which part of the human ear gives ‘Dynamic balance’ and ‘Static balance’  to the body? 

(iii) Explain how the human eye adapts itself to bright light and dim light. 

(iv) What is Parthenocarpy? Give one example. 

(v) Mention any two objectives of ‘Swachh Bharat Abhiyan’. 

(b) The diagram given below represents a system in the human body.  

Study the diagram and answer the following questions: 

(i) Identify the system. 

(ii) Label the parts marked 5 and 6. 

(iii) Name the two hormones secreted by 1. 

(iv) Mention the number and the name of the part involved in fertilization and  implantation from the above diagram. 

(v) Mention the surgical methods of contraception in:  

1. Human males. 

2. Human females.

Answer:

(a) (i) Brain – Outer, grey matter has cytons and inner white matter has axons.

            Spinal Cord – Outer, white matter has axons and inner grey matter has cytons.

(ii) Dynamic – semi-circular canals/ducts/tubes

       Static – utriculus, sacculus, utricle, saccule, vestibule

(iii) Bright light – Pupils constrict, Rhodopsin is bleached.

       Dim light – Pupils dilate, Rhodopsin is regenerated.

(iv) Formation of fruit without fertilisation e.g. grapes, water melon, banana, papaya.

(v) – To clean roads, streets and buildings in cities and towns.

      – To eliminate open defecation

      – To build and monitor the use of latrines

      – To manage solid and liquid waste

(b) (i) Female reproductive system

(ii) 5 – Oviducal funnel

      6 – Cervix

(iii) Oestrogen, Progesterone.

(iv) Fertilisation – 2, Oviduct/Fallopian tube

       Implantation – 3, Uterus

(v) 1 – Vasectomy

      2 – Tubectomy

 

CHEMISTRY 

SCIENCE Paper – 2 

SECTION-I 

Q.1 (a) Choose the correct answer from the options given below: 

    (i) An electrolyte which completely dissociates into ions is: 

         A. Alcohol  

         B. Carbonic acid 

          C. Sucrose  

          D. Sodium hydroxide 

    (ii) The most electronegative element from the following elements is: 

           A. Magnesium 

           B. Chlorine  

           C. Aluminium 

           D. Sulphur 

   (iii) The reason for using Aluminium in the alloy duralumin is: 

          A. Aluminium is brittle. 

          B. Aluminium gives strength. 

          C. Aluminium brings lightness. 

          D. Aluminium lowers melting point. 

   (iv) The drying agent used to dry HCl gas is: 

         A. Conc. H2SO4 

         B. ZnO 

         C. Al2O3 

         D. CaO 

   (v) A hydrocarbon which is a greenhouse gas is: 

        A. Acetylene 

        B. Ethylene 

        C. Ethane 

        D. Methane 

(b) Fill in the blanks with the choices given in brackets: 

(i) Conversion of ethanol to ethene by the action of concentrated sulphuric  acid is an example of ____________. (dehydration / dehydrogenation /dehydrohalogenation) 

(ii) When sodium chloride is heated with concentrated sulphuric acid below 200^oC, one of the products formed is ____________. (sodium hydrogen sulphate / sodium sulphate / chlorine) 

(iii) Ammonia reacts with excess chlorine to form ____________. (nitrogen / nitrogen trichloride / ammonium chloride) 

(iv) Substitution reactions are characteristic reactions of ____________ (alkynes / alkenes / alkanes) 

(v) In Period 3, the most metallic element is ____________. (sodium / magnesium / aluminium) 

(c) Write a balanced chemical equation for each of the following reactions: 

     (i) Reduction of copper (II) oxide by hydrogen. 

     (ii) Action of dilute sulphuric acid on sodium hydroxide. 

    (iii) Action of dilute sulphuric acid on zinc sulphide. 

    (iv) Ammonium hydroxide is added to ferrous sulphate solution. 

    (v) Chlorine gas is reacted with ethene. 

(d) State one observation for each of the following:  

     (i) Concentrated nitric acid is reacted with sulphur. 

    (ii) Ammonia gas is passed over heated copper (II) oxide. 

   (iii) Copper sulphate solution is electrolysed using copper electrodes. 

   (iv) A small piece of zinc is added to dilute hydrochloric acid. 

   (v) Lead nitrate is heated strongly in a test tube. 

(e) (i) Calculate:  

       1. The number of moles in 12g of oxygen gas. [O = 16] 

       2. The weight of 10²² atoms of carbon.  

            [C = 12, Avogadro’s No. = 6 x 10²³] 

     (ii) Molecular formula of a compound is C6 H18 O3. Find its empirical formula. (f)

(i) Give the IUPAC name of the following organic compounds:

(ii) What is the special feature of the structure of ethyne? 

(iii) Name the saturated hydrocarbon containing two carbon atoms. 

(iv) Give the structural formula of Acetic acid. 

(g) Give the appropriate term defined by the statements given below: 

     (i) The formula that represents the simplest ratio of the various elements present in one molecule of the compound. 

     (ii) The substance that releases hydronium ion as the only positive ion when dissolved in water. 

     (iii) The tendency of an atom to attract electrons towardsitself when combined in a covalent compound. 

     (iv) The process by which certain ores, specially carbonates, are converted to oxides in the absence of air. 

    (v) The covalent bond in which the electrons are shared equally between the combining atoms. 

(h) Arrange the following according to the instructions given in brackets:  

      (i) K, Pb, Ca, Zn. (In the increasing order of the reactivity) 

     (ii) Mg²⁺, Cu²⁺, Na¹⁺, H¹⁺  (In the order of preferential discharge at the  cathode) 

     (iii) Li, K, Na, H (In the decreasing order of their ionization potential) 

     (iv) F, B, N, O (In the increasing order of electron affinity) 

    (v) Ethane, methane, ethene, ethyne. (In the increasing order of the  molecular weight) [H = 1, C = 12] 

SECTION II 

Q.2 (a) Draw the electron dot structure of: 

    (i) Nitrogen molecule  [N = 7] 

   (ii) Sodium chloride     [Na = 11, Cl = 17] 

   (iii) Ammonium ion     [N = 7, H = 1] 

(b) The pH values of three solutions A, B and C are given in the table. Answer the following questions: 

Solution	pH value
A	12
B	2
C	7

    (i) Which solution will have no effect on litmus solution? 

     (ii) Which solution will liberate CO2 when reacted with sodium carbonate? 

     (iii) Which solution will turn red litmus solution blue? 

(c) Study the extract of the Periodic Table given below and answer the questions that follow. Give the alphabet corresponding to the element in question.  DO NOT repeat an element. 

     (i) Which element forms electrovalent compound with G? 

    (ii) The ion of which element will migrate towards the cathode during electrolysis? 

   (iii) Which non-metallic element has the valency of 2? 

   (iv) Which is an inert gas? 

Q.3 (a) Name the particles present in: 

     (i) Strong electrolyte 

    (ii) Non- electrolyte 

    (iii) Weak electrolyte 

(b) Distinguish between the following pairs of compounds using the reagent given in the bracket. 

    (i) Manganese dioxide and copper (II) oxide. (using concentrated HCl) 

    (ii) Ferrous sulphate solution and ferric sulphate solution. (using sodium hydroxide solution) 

   (iii) Dilute hydrochloric acid and dilute sulphuric acid. (using lead nitrate solution) 

(c) Choose the method of preparation of the following salts, from the methods given in the list: 

[List: A. Neutralization  B. Precipitation  C. Direct combination   D. Substitution] 

      (i) Lead chloride 

      (ii) Iron (II) sulphate 

      (iii) Sodium nitrate  

      (iv) Iron (III) chloride 

Q.4 (a) Complete the following equations: 

     (i) S + conc. HNO3 → 

    (ii) C + conc. H2SO4 → 

    (iii) Cu + dil. HNO3 → 

(b) Write a balanced chemical equation for the preparation of: 

     (i) Ethene from bromoethane 

    (ii) Ethyne using calcium carbide 

    (iii) Methane from sodium acetate. 

(c) Name the following organic compounds: 

    (i) The compound with 3 carbon atoms whose functional group is a carboxyl.    

    (ii) The first homologue whose general formula is CnH2n. 

   (iii) The compound that reacts with acetic acid to form ethyl ethanoate. 

    (iv) The compound formed by complete chlorination of ethyne. 

Q.5 (a) Give the chemical formula of: 

   (i) Bauxite 

   (ii) Cryolite 

   (iii) Sodium aluminate 

(b) Answer the following questions based on the extraction of aluminium from alumina by Hall-Heroult’s Process.:  

     (i) What is the function of cryolite used along with alumina as the  electrolyte?  

    (ii) Why is powdered coke sprinkled on top of the electrolyte? 

    (iii) Name the electrode, from which aluminium is collected. 

(c) Match the alloys given in column I to the uses given in column II:

COLUMN I	COLUMN II
(i) Duralumin	A. Electrical fuse
(ii) Solder	B. Surgical instruments
(iii) Brass	C. Aircraft body
(iv) Stainless Steel	D. Decorative articles

Q.6 (a) Identify the substances underlined: 

    (i) The catalyst used to oxidise ammonia. 

    (ii) The organic compound which when solidified, forms an ice like mass.  

     (iii) The dilute acid which is an oxidizing agent. 

(b) Copper sulphate solution reacts with sodium hydroxide solution to form a precipitate of copper hydroxide according to the equation: 

                       2NaOH + CuSO4 → Na2SO4 + Cu(OH)2 ↓ 

        (i) What mass of copper hydroxide is precipitated by using 200 gm of sodium hydroxide? 

                          [H = 1, O = 16, Na = 23, S = 32, Cu = 64] 

        (ii) What is the colour of the precipitate formed? 

(c) Find the empirical formula and the molecular formula of an organic compound  

      from the data given below: 

      C = 75.92%, H = 6.32% and N = 17.76%  

     The vapour density of the compound is 39.5.  

      [C = 12, H = 1, N = 14] 

Q.7 (a) Name the gas evolved in each of the following cases:  

    (i) Alumina undergoes electrolytic reduction.  

   (ii) Ethene undergoes hydrogenation reaction. 

   (iii) Ammonia reacts with heated copper oxide. 

(b) Study the flow chart given and give balanced equations to represent the reactions A, B and C: 

(c) Copy and complete the following table which refers to the industrial method for the preparation of ammonia and sulphuric acid: 

Name of the compound	Name of the process	Catalytic equation  (with the catalyst)
Ammonia	(i)__________	(ii)__________
Sulphuric acid	(iii)__________	(iv)__________

SCIENCE PHYSICS 

SCIENCE Paper – 1 

Q.1 (a) The diagram below shows a claw hammer used to remove a nail: 

    (i) To which class of lever does it belong? 

   (ii) Give one more example of the same class of lever mentioned by you in (i) for which the mechanical advantage is greater than one. 

(b) Two bodies A and B have masses in the ratio 5:1 and their kinetic energies are in the ratio 125:9. Find the ratio of their velocities. 

(c) (i) Name the physical quantity which is measured in calories.  

     (ii) How is calorie related to the S.I unit of that quantity? 

(d) (i) Define couple. 

     (ii) State the S.I. unit of moment of couple. 

(e) (i) Define critical angle. 

     (ii) State one important factor which affects the critical angle of a given medium. 

 

Q.2 (a) An electromagnetic radiation is used for photography in fog. 

     (i) Identify the radiation. 

    (ii) Why is this radiation mentioned by you, ideal for this purpose? 

(b) (i) What is the relation between the refractive index of water with respect to air (aµw) and the refractive index of air with respect to water (wµa). 

     (ii) If the refractive index of water with respect to air (aµw) is 5/3. Calculate the refractive index of air with respect to water (wµa). 

(c) The specific heat capacity of a substance A is 3,800 Jkg^-1K^-1and that of a substance B is 400 Jkg^-1K^-1. Which of the two substances is a good conductor of heat? Give a reason for your answer.  

(d) A man playing a flute is able to produce notes of different frequencies. If he  closes the holes near his mouth, will the pitch of the note produced, increase or decrease? Give a reason. 

(e) The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42^o. Complete the path of the ray PQ till itemerges out of the block. [Write necessary angles.] 

 

Q.3 (a) (i) If the lens is placed in water instead of air, how does its focal length change? 

    (ii) Which lens, thick or thin has greater focal length? 

(b) Two waves of the same pitch have amplitudes in the ratio 1: 3. What will be the ratio of their:  

     (i) intensities and  

    (ii) frequencies? 

(c) How does an increase in the temperature affect the specific resistance of a: 

     (i) Metal and 

    (ii) Semiconductor? 

(d) (i) Define resonant vibrations. 

     (ii) Which characteristic of sound, makes it possible to recognize a person by his voice without seeing him? 

(e) Is it possible for a hydrogen (₁H¹) nucleus to emit an alpha particle? Give a reason for your answer. 

 

Q.4 (a) Calculate the effective resistance across AB: 

(b) (i) State whether the specific heat capacity of a substance remains the same 

           when its state changes from solid to liquid. 

     (ii) Give one example to support your answer. 

(c) A magnet kept at the centre of two coils A and B is moved to and fro as   

     shown in the diagram. The two galvanometers show deflection. 

            State with a reason whether: 

                            x > y 

                               or 

                            x < y. [x and y are magnitudes of deflection.] 

(d) (i) Why is a nuclear fusion reaction called a thermo nuclear reaction? 

     (ii) Complete the reaction: 

                   ³He2 + ²H1 ⁴He2 + …………….. + Energy 

(e) State two ways to increase the speed of rotation of a D.C. motor. 

 

SECTION II 

Q.5 (a) A body of mass 10 Kg is kept at a height of 5 m. It is allowed to fall and reach the ground.  

    (i) What is the total mechanical energy possessed by the body at the height of 2 m assuming it is a frictionless medium? 

     (ii) What is the kinetic energy possessed by the body just before hitting the ground? Take g = 10 m / s². 

(b) A uniform meter scale is in equilibrium as shown in the diagram: 

(i) Calculate the weight of the meter scale. 

(ii) Which of the following options is correct to keep the ruler in equilibrium when 40 gf wt is shifted to 0 cm mark? 

                    F is shifted towards 0 cm. 

                                    or 

                   F is shifted towards 100 cm. 

(c) The diagram below shows a pulley arrangement: 

(i) Copy the diagram and mark the direction of tension on each strand of the string. 

(ii) What is the velocity ratio of the arrangement? 

(iii) If the tension acting on the string is T, then what is the relationship between T and effort E? 

(iv) If the free end of the string moves through a distance x, find the distance by  which the load is raised. 

 

Q.6 (a) How does the angle of deviation formed by a prism change with the increase in the angle of incidence?  

      Draw a graph showing the variation in the angle of deviation with the angle of  incidence at a prism surface. 

(b) A virtual, diminished image is formed when an object is placed between the optical centre and the principal focus of a lens.  

(i) Name the type of lens which forms the above image. 

(ii) Draw a ray diagram to show the formation of the image with the above stated characteristics. 

(c) An object is placed at a distance 24 cm in front of a convex lens of focal length 8 cm. 

     (i) What is the nature of the image so formed? 

     (ii) Calculate the distance of the image from the lens. 

     (iii) Calculate the magnification of the image. 

 

Q.7 (a) It is observed that during march-past we hear a base drum distinctly from a distance compared to the side drums. 

    (i) Name the characteristic of sound associated with the above observation.  

    (ii) Give a reason for the above observation. 

(b) A pendulum has a frequency of 4 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after  6 vibrations of the pendulum. If the velocity of sound in air is 340  m/s, find the  distance between the cliff and the observer. 

(c) Two pendulums C and D are suspended from a wire as shown in the figure given below. Pendulum C is made to oscillate by displacing it from its mean position. It is seen that D also starts oscillating. 

(i) Name the type of oscillation, C will execute.

(ii) Name the type of oscillation, D will execute.

(iii) If the length of D is made equal to C then what difference will you notice in the oscillations of D?

(iv) What is the name of the phenomenon when the length of D is made equal to C?

 

Q.8 (a) (i) Write one advantage of connecting electrical appliances in parallel combination. 

      (ii) What characteristics should a fuse wire have? 

      (iii) Which wire in a power circuit is connected to the metallic body of the appliance? 

(b) The diagram below shows a dual control switch circuit connected to a bulb. 

(i) Copy the diagram and complete it so that the bulb is switched ON. 

(ii) Out of A & B which one is the live wire and which one is the neutral wire?

(C)

 The diagram above shows a circuit with the key k open. Calculate:

(i) the resistance of the circuit when the key k is open.

(ii) the current drawn from the cell when the key k is open. 

(iii) the resistance of the circuit when the key k is closed. 

(iv) the current drawn from the cell when the key k is closed. 

 

Q.9  (a) (i) Define Calorimetry. 

     (ii) Name the material used for making a Calorimeter.  

     (iii) Why is a Calorimeter made up of thin sheets of the above material answered in (ii)? 

(b) The melting point of naphthalene is 80°C and the room temperature is 30°C. 

      A sample of liquid naphthalene at 100°C is cooled down to the room temperature.  Draw a temperature time graph to represent this cooling. In the graph, mark the  region which corresponds to the freezing process. 

(c) 104 g of water at 30°C is taken in a calorimeter made of copper of mass 42 g. 

      When a certain mass of ice at 0°C is added to it, the final steady temperature of  the mixture after the ice has melted, was found to be 10°C. Find the mass of ice  added. [Specific heat capacity of water = 4.2 Jg^-1°C^-1; Specific latent heat of  fusion of ice = 336 Jg^-1; Specific heat capacity of copper = 0.4  Jg^-1°C^-1] 

 

Q.10 (a) Draw a neat labeled diagram of an A.C. generator. 

(b) (i) Define nuclear fission. 

     (ii) Rewrite and complete the following nuclear reaction by filling in the atomic number of Ba and mass number of Kr: 

(c) The diagram below shows a magnetic needle kept just below the conductor AB which is kept in North South direction. 

(i) In which direction will the needle deflect when the key is closed? 

(ii) Why is the deflection produced? 

(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB? 

(iv) Name one device which works on this principle.