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Time Allowed: 3 hours Maximum Marks: 80 General Instructions:
- This question paper consists of 39 questions in 5 sections.
- All questions are compulsory. However, an internal choice is provided in some questions. A student is expected to attempt only one of these questions.
- Section A consists of 20 objective-type questions carrying 1 mark each.
- Section B consists of 6 Very Short questions carrying 02 marks each. Answers to these questions should be in the range of 30 to 50 words.
- Section C consists of 7 Short Answer type questions carrying 03 marks each. Answers to these questions should be in the range of 50 to 80 words.
- Section D consists of 3 Long Answer type questions carrying 05 marks each. Answers to these questions should be in the range of 80 to 120 words.
- Section E consists of 3 source-based/case-based units of assessment of 04 marks each with sub-parts. Section A
a) Formation of a precipitate b) Change in temperature c) Evolution of a gas d) Both change in temperature and evolution of gas
- Which characteristic is observed by the reaction shown in the given image? [1]
a) Both Precipitation reaction and Double displacement reaction b) Double displacement reaction c) Decomposition reaction d) Precipitation reaction
2. BaCl 2 + Na 2 SO 4 →BaSO 4 + 2NaCl. It is type of: [1]
a) Acetic acid b) Methanoic acid
- Acid present in tomato is: [1]
c) Lactic acid d) Oxalic acid a) Potassium salts b) Calcium salts c) Magnesium salts d) Sodium salts
- Which of the following are called soft soaps? [1]
a) Tube B and C b) Tube B c) Tube A d) Tube A and C
- Take three boiling tubes A, B and C. Pour some water in test tube A Put iron nails in it and cork it. Pour boiled distilled water in another test tube B and put iron nails in it. Add 1 ml of oil over it such that oil floats over it and prevents the air from entering. Take some iron nails in test tube C and put some anhydrous calcium chloride in it and cork it. Leave all the three test tubes for one day and then observe.
In which test tube nail is rusted?
[1]
a) A and D b) B and C c) A and C d) All of these
- Which oxide will turn blue litmus solution to red? A. SO B. MgO^2 C. Na 2 O D. NO 2
[1]
a) - COOH b) - CHO c) - CO - d) - OH
- Butanone is a four carbon compound with the functional group : [1]
a) Ureter b) Urethra c) Urinary bladder d) Nephron
In the excretory system of human beings, some substances in the initial filtrate such as glucose, amino acids, salts and water are selectively reabsorbed in [1]
The genotype for the height of an organism is Tt. What conclusion may be drawn from this? [1]
Section B
Section C
a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not the correct explanation of A. c) A is true but R is false. d) A is false but R is true. a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not the correct explanation of A. c) A is true but R is false. d) A is false but R is true.
- Assertion (A): Reason (R): Spermicides kill the sperms. Vaginal pills contain spermicides. [1]
a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not the correct explanation of A. c) A is true but R is false. d) A is false but R is true.
- Assertion (A): current through the coil is doubled. The magnetic field intensity at the centre of a circular coil carrying current changes, if the Reason (R): The magnetic field intensity is dependent on current in conductor.
[1]
a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not the correct explanation of A. c) A is true but R is false. d) A is false but R is true.
- Assertion (A): compounds. In an ecosystem, the function of producers is to convert organic compounds into inorganic Reason (R): Green plants, the producers, transduce solar energy.
[1]
Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also. [2]
Define the term pollination. Differentiate between self-pollination and cross-pollination. What is the significance of pollination? [2]
What are the components of the transport system in highly organized plants? OR [2]
What are the two phases of photosynthesis reactions?A concave lens has a focal length of 10 cm. An object 2.5 cm high is placed 30 cm from the lens. Determine the
position and size of the image.Give some examples along with reasons of insecticides that are banned due to their fatal effects.^ [2][2] What is ozone and how does it affect any ecosystem?^ OR
What type of lens we wear if we are suffering from myopia? [2]
Nikita took Zn, Al, Cu, Fe, Mg and Na metal and put each metal in cold water and then hot water. She reacted the metal with steam (i) Name the metal which reacts with cold water. (ii) Which of the above metals react with steam?
[3]
Section D
(iii) Name the metal which reacts with hot water. (iv) Arrange these metals in order of increasing reactivity.
- Name a metal/non-metal: i. Which makes iron hard and strong?
iii^ ii..^ Which is alloyed with any other metal to make an amalgam?Which is used to galvanize iron articles? iv. Whose articles when exposed to air form a black coating?
[3]
Give reasons:^ OR b^ a.. Platinum, gold and silver are used to make jewellery.Sodium, potassium and lithium are stored under oil. d^ c.. Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
- Draw the diagram of part of leaf from which transpiration takes place. Explain stomatal or foliar transpiration.^ e.^ Lemon or tamarind juice are effective in cleaning tarnished copper vessels. [3]
- In pea plant, round seed is dominant over the wrinkled. If a cross is carried out between these two plants, give answer to the following questions.
ii^ i..^ Mention the genes for the traits of parents.State the trait of F 1 hybrids. iii. Write the ratio of F 2 progeny obtained from this cross. What is the name of the cross?
[3]
- What is atmospheric refraction? Explain with the help of a labelled diagram that the position of a star as seen by us is not its true position. [3]
- a. Calculate the resistance of a metal wire of length 2 m and area of cross-section 1.55 10 -6^ m^2. (Resistivity b. of the metal is 2.8Why are alloys preferred over pure metals to make the heating elements of electrical heating devices?^10 -8^ m)
×^ [3]
× Ω
- i. An electric lamp of 100 ohms, a toaster of resistance 50 ohms and a water filter of resistance 500 ohms are connected in parallel to a 220V source. what is the resistance of the electric iron connected to the same
ii. source that takes as much current as all the three appliances and what is the current through it?Which uses more energy, a 250 W TV set for 1 hour or a 1,200 W toaster for 10 minutes?
[3]
- (^) iii.. Compare soaps and detergents on the basis of their composition and cleansing action in hard water.What happens when ethanol is treated with sodium metal? State the behaviour of ethanol in this reaction. iii iv.. Draw the structure of cyclohexane.Name the following compound.
[5]
Draw the possible isomers of the compound with molecular formula C^ OR 3 H 6 O and also give their electron dot structures.
H − C O ||− C H^ H |^ |− H
- Why are budding, fragmentation and regeneration all considered as asexual types of reproduction? With neat [5]
obviously, geotropism.
OR
(a) What has represented by the given activities? Do old parts of the shoot and root change direction? Is there any difference in the direction of the new (b)(c) growth? What can we conclude from this activity?
- Read the text carefully and answer the questions:^ What is geotropism? A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminum rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions :
[4]
OR
(a) State the condition under which the displacement of the rod is largest for the same magnitude of current flowing through it. (b) State the rule that determines the direction of the force on the conductor AB. i. If the U shaped magnet is held vertically and the aluminum rod is suspended horizontally with its end B towards due north, then on passing current through the rod from B to A as shown, in which direction will the rod be displaced? ii. Name any two devices that use current carrying conductors and magnetic field.
(c)
Draw the pattern of magnetic field lines produced around a current-carrying straight conductor held vertically on horizontal cardboard. Indicate the direction of the field lines as well as the direction of the current flowing through the conductor.
Section A (d) Explanation: Both change in temperature and evolution of gas Two observations are made that may suggest that a chemical reaction has taken place in the given image are ii^ i..^ evolution of a gas andchange in temperature. A pop sound is produced when zinc granules and dilute produced during the reaction. The flask also becomes warm showing that there is a change in temperature. Hence, the chemical sulphuric acid reacts together which shows that hydrogen gas is reaction between zinc and dilute sulphuric acid is characterized by the evolution of hydrogen gas and change in temperature. Zn + H 2 SO 4 → ZnSO 4 + H 2 ↑ + Heat
(a) Explanation: Both Precipitation reaction and Double displacement reaction Double decomposition takes place, due to the exchange of ions between the 2 substances. A white precipitate of barium sulphate is formed. BaCl BaSO 2 4 + Na is insoluble in water. NaCl dissolves in water. 2 SO 4 BaSO 4 + 2NaCl BaSO NaCl is common salt of Sodium Chloride 4 is Barium Sulphate
(d) Oxalic acid Explanation: in tomatoes. Each 100 g More than ten different types of acids, including citric acid, malic acid, ascorbic acid, and oxalic acid, are present serving of tomatoes contains about 50 mg of oxalic acid. So, the main acid found in tomatoes is oxalic
acid. (a) Potassium salts 5.^ Explanation:^ Potassium salts (c) Explanation: Tube A Iron nails get rusted in test tube A because both air and water are present in it. Iron nails do not get rusted in B
because there is water but no air. In C, rusting will not take place because there is neither air nor water. (a) A and D Explanation: oxides (Oxides of Mg and Na) are basic in nature. An acidic oxide will turn blue litmus red. Non-metal oxides (Oxides of S and N) are acidic in nature. Metal
(c) - CO - Explanation: Butanone (CH 3 COCH 2 CH 3 ) is the second member of ketones. It is a four carbon compound with ketone functional group (- CO -). The ketone functional group has two free valencies which are satisfied by one methyl C 2 H 5 ) group. ( -CH 3 ) group and one ethyl ( -
(d) Nephron Explanation: Nephron
Solution
Explanation: spermicides which kill the sperms. Vaginal pills are the chemical methods of birth control. The vaginal pills contain the chemicals called
(a) Explanation: Both A and R are true and R is the correct explanation of A. The magnetic field at the centre of circular coil is directly proportional to the current flowing through it.
So if current through coil is doubled then magnetic field becomes double. (a) Both A and R are true and R is the correct explanation of A. Explanation: Both A and R are true and R is the correct explanation of A. Section B
Soaps are sodium or potassium salts of long chain fatty acids. The action of a soap is based on the presence of both hydrophilic and hydrophobic groups in a soap molecule. This action emulsifies the oily dirt and helps in its removal. The two ends of a soap molecule have different properties. When soap is added to water, the ionic, hydrophilic end of soap molecule dissolves in water. The hydrocarbon chain of soap molecule is hydrophobic and it dissolves in hydrocarbons i.e. links with oily dirt. The hydrocarbon chain of soap molecule orients towards the oil droplet while the ionic end orients towards water (polar solvent). This is how, soap molecules form structures called micelles where the oily dirt is collected in the centre. Thus, soap micelles help in dissolving dirt in water. Micelles stay in solution as colloids and the dirt suspended in the micelles is easily rinsed away. Micelle formation will not take place in a solvent like ethanol because ethanol will dissolve the hydrocarbon chain of a soap molecule also.
Pollination is the act of transferring pollen grains from the male anther of a flower to the female stigma. The goal of every living organism, including plants, is to create offspring for the next generation. One of the ways that plants can produce offspring is by making seeds. Seeds contain the genetic information to produce a new plant. Self-pollination: i. It is the transfer of pollen grains from the anther of the stamen to the stigma of the carpel of the same flower or different flower of the same plant. iii^ ii..^ It does not require external agents.It does not introduce variation. iv v.. It is a sure and economical method.It avoids mixing or dilution of the original characters. Cross-pollination:^ vi.^ The progeny becomes weaker after every generation ii^ i.. It is the transfer of pollen grains from the anther to the stigma of different flowers of different plants.It requires external agents like wind, insects, etc. to carry out pollination. iii iv.. It introduces variation and adaptability.It is not economical and is highly wasteful. vi^ v.. Good characters of a race can be diluted.The progeny becomes healthier and better fitted for existence.
Components of the transport system in plants 1. Xylem tissue – Vessels and tracheoles of roots, stems and leaves are concerned with transport of water and minerals.
Phloem transports food, amino acid and other substances. OR The two phases of photosynthesis reactions are as follows: a) Light reaction: In light-dependent reactions, the energy from sunlight is absorbed by chlorophyll and converted into chemical energy in the form of electron carrier molecules like ATP and NADPH. It takes place in the thylakoid of the grana of the
chloroplasts. b) Dark reaction: In light-independent reactions (Calvin Cycle), carbohydrate molecules are assembled from carbon dioxide using
- the chemical energy harvested during the light-dependent reactions. It takes place in the stroma of the chloroplasts.Since the lens is concave, hence f is negative Given: u = - 30 cm; f= - 10 cm; h = 2.5 cm; v = ?; h' =?
The lens formula for concave lens is
v = -7.5 cm The negative sign indicates the virtual nature of the image. The image is at a distance of 7.5 cm from lens (in front of lens). The magnification m = = = +0. The positive sign with the magnification indicates that the image formed erect. The size of the image is determined by h'. h' =^ = m = = 0.625 m
Thus the image formed is virtual and erect. It is at a distance of 7.5 cm from lens and its size is 0.625 cm.Many insecticides such as aldicarb, aldrin, chlorodane and dieldrin with many others have been banned in India due to their harmful effects on life. These pesticides are non-biodegradable and get accumulated in the body of organisms and the concentration of these chemicals increases with each trophic level, thus, killing a large number of organisms and putting various health risks to others. OR Ozone is a form of oxygen. It is formed by three atoms of oxygen (Os), whereas normal oxygen molecule is diatomic (02). Oxygen is essential for all aerobic forms of life and for combustion activities. Ozone, is a deadly poison. Very little of it is present in lower part of the atmosphere called troposphere. In the stratosphere, ozone layer comprises high concentration of ozone some 18-26 km above. Ozone performs an essential function. It shields the surface of the earth from the harmful ultraviolet (UV)
radiation of the sun.We rarely use concave lens as is usually supposed. We often use convexo concave lens or any other diverging lens.
(i) Na^ Section C (ii) Al, Zn, Fe (iii) Mg
(iv) Na>Mg>Al>Zn>Fe>Cu i.Carbon makes iron hard and strong. iii^ ii..^ Mercury is alloyed with any other metal to make an amalgam.Zinc used to galvanize iron articles. iv. Silver article when exposed to air from a black coating. OR a. Platinum, gold and silver are used to make jewelry because of their bright shiny surface and high resistance to corrosion. Also they have high malleability and ductility.
(^1) − =^1^ v^ −^^ u^1 =^1^ f v (^1) v = −30 1011 − 301 −10^1 (^1) v =^ −3−1 30
1 v^ u^ =^ −7.5^30 4 h h ′ h × m 2.5 × 0.
Thus, putting all the values, we get R = R = R = 3.61 10 - Thus, The resistance of the metal wire is 3.61 10 - b. Alloys are used in electrical heating devices rather than pure metals because the resistivity of an alloy is more than the resistivity of pure metal. Also, the melting point of an alloy is high, so it does not melt or oxidize easily even at a higher
- i.^ temperature.Combined resistance of 100 , 50 and 500 in parallel i.e. R Resistance of electric iron = 31.25p is given by ii. Current through electric iron =Energy consumed E 1 = P 1 t 1 = 250 W 1h = 250 3600s E E 12 = 900000J= P 2 t 2 = 12000W 10 min E E 22 = 1200= 720000J 600s 250 TV set consumes more energy. Section D
- i.Difference between soap and detergent: Property Soap Detergent
Composition Soaps are sodium or potassium salts of long-chain carboxylic acids/ fatty acids^ Detergents are the ammonium or sulphonate salts of long-chain carboxylic acids. Cleansing action in hard water Ca insoluble substance (scum) with soap.2+^ and Mg2+^ are present in hard water and forms Detergents work well with hard and soft water both. ii. Ethanol reacts with sodium metal to produce sodium ethoxide (CH soluble in water. 3 CH 2 ONa) and hydrogen gas. This salt is colourless and
iii. The reaction is used to test the presence of ethanol or alcohol as hydrogen gas evolved during the reaction.Structure of cyclohexane:
iv. The name of the compound is ethanol. OR There are four isomers possible for the molecular formula C i. 3 H 6 O. These are as follows: electron dot structure:
2.8× 5.6× 1.55× 1010 −8−2 10 Ω−−6 m (^) m×2 2 m 1.55 × Ω × Ω
RP^1 =^1001 Ω^ +^501 Ω^ +^5001 =Ω^ 5+10+1^500 =^1254 = 31. V R^ Ω = (^) 31.25 (^220) = 7.04 A × J S × J^ × S × ∴ Ω
2 Na + 2 C H Ethanol 3 C H 2 OH → 2 C Sodium ethoxide H 3 C H 2 ONa + H 2
CH (^) 3 C Propanal H 2 CHO
ii. Prop - 2 - one electron dot structure:
iii. electron dot structure: iv. electron dot structure:
- Budding, fragmentation and regeneration are all example of asexual Male and female gametes are not involved in the reproduction. Thus in all of the three process no variation is produced. reproduction because all of them involve only one parent. Planaria can be cut into any number of pieces and each piece grows into a complete organism. This process is known as regeneration (see fig.) Regeneration is carried out by specialised cells known as neoblast ( adult stem cells ). These cells proliferate and produce large numbers of cells. From this mass of cells, different cells undergo changes to become various cell types and tissues, giving rise to whole new organism with same DNA content as its parent. These changes take place in an organised manner referred to as development.
i. The figure represents the phenomenon of phototropism i.e., response of plants to light.^ OR iii^ ii..^ The plant hormone auxin is invoved in the phenomenon of phototropism.Plants show their growth towards light and this movement is caused by the action of auxin hormone. Auxin is synthesised by the meristematic tissue which is present at the tip of shoot, roots etc. In the above figure the plant bends towards the light. Auxin hormone is synthesised in the tip of the stem and moves towards the side of the plant not receiving light. Due to more
C H 3 − CH Prop - 1 - enol = CH − OH
C H 2 = CH Prop - 2 - enol − CH 2 − OH
Movements in the organs of a plant due to gravity are known as geotropism. This causes the roots to bend down towardsOR
- Read the text carefully and answer the questions:^ the soil. A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminum rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions :
OR
(i)(ii) These activities show tropic movements in plants due to their growth. Yes, old parts of the shoot and root change direction and there is a difference in the direction of new growth. (iii) Movement is related to stimulus i.e. plant organs either move towards the source of stimulus or away from it. Stimuli that cause movements in plants are gravity, light, touch, water, and chemical substances.
(i) The displacement of the conductor is maximum when the direction of the current is at right angles to the direction of the magnetic field. The rule that determines the direction of the force on the conductor AB is Fleming's left-hand rule. According to Fleming's left-hand rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of the magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or force.
(ii)
ii^ i.. According to Fleming's left-hand rule, the rod will get displaced upwards.Devices that use current-carrying conductors and magnetic fields are electric motors, electric generators, loudspeakers, microphones, etc.
(iii)
