Q1
mcq
1 mark
From the following, select a process in which combination reaction occurs:
- A. Black and white photography
- B. Burning of carbon (coal)
- C. Burning of methane
- D. Refining of copper
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Q2
mcq
Select exothermic processes from the following:
(i) Dilution of acid
(ii) Burning of natural gas
(iii) Evaporation of water
(iv) Electrolysis of water
- A. (i) and (ii)
- B. (ii) and (iii)
- C. (iii) and (iv)
- D. (i) and (iv)
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Q3
mcq
The most malleable metals are:
- A. Iron and gold
- B. Copper and silver
- C. Silver and gold
- D. Gold and copper
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Q4
mcq
Consider the reactions of dil. hydrochloric acid with the following metals: Aluminium, Copper, Iron, Magnesium and Zinc. The correct observation is:
- A. Most vigorous reaction with aluminium and no reaction with iron
- B. Most vigorous reaction with magnesium and no reaction with iron
- C. Most vigorous reaction with magnesium and no reaction with copper
- D. Most vigorous reaction with zinc and no reaction with copper
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Q5
mcq
The number of covalent bond(s) present in a nitrogen molecule is/are: (Atomic number of nitrogen is 7)
- A. 1
- B. 3
- C. 5
- D. 7
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Q6
mcq
The valves in the human heart ensure that:
(i) Oxygen-rich blood flows from left atrium to left ventricle only.
(ii) Deoxygenated blood flows from left atrium to left ventricle only.
(iii) Oxygen-rich blood flows from right atrium to right ventricle only.
(iv) Deoxygenated blood flows from right atrium to right ventricle only.
- A. (i) and (iii)
- B. (ii) and (iv)
- C. (i) and (iv)
- D. (ii) and (iii)
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Q7
mcq
The part of the hindbrain present immediately above the medulla is:
- A. Cerebellum
- B. Pons
- C. Cerebrum
- D. Spinal cord
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Q8
mcq
Application of Abscisic acid on plants promotes:
- A. Development of fruits
- B. Wilting of leaves
- C. Elongation of stem
- D. Formation of flowers
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Q9
mcq
The end product of meiosis in a reproductive cell in plants is:
- A. Zygote
- B. Pollen grains
- C. Sperms
- D. Egg
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Q10
mcq
In garden pea, violet colour flower is the dominant trait over white colour flower which is the recessive trait. When parent plant with violet coloured flowers (Vv) is crossed with a parent plant with white flowers, the possible percentage of occurrence of traits in the F1 progeny would be:
- A. 100% violet
- B. 50% violet, 50% white
- C. 25% violet, 75% white
- D. 75% violet, 25% white
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Q16
mcq
Which one of the following statements is incorrect about the effect on our environment as a result of our activities?
- A. Improvement in our lifestyle has resulted in greater amounts of waste.
- B. Packaging of materials h
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Q17
mcq
Assertion (A): Decomposition of vegetable matter into compost is an exothermic reaction.
Reason (R): Decomposition reactions need energy to break down the reactants.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q18
mcq
Assertion (A): Transpirational pull helps in the absorption and upward movement of water and dissolved minerals in plants.
Reason (R): The effect of root pressure in transport of water is more significant at night.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q19
mcq
Assertion (A): In our homes we receive supply of electric power through a main supply. One of the wires in this supply, usually with red insulation, is called live wire and another wire with green insulation is called neutral wire.
Reason (R): In our country, the potential difference between the live wire and the neutral wire is 220 volts.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q20
mcq
Assertion (A): Due to scattering of sunlight, the clear sky predominantly appears blue.
Reason (R): The wavelength of blue light is nearly 1.8 times the wavelength of red light.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
- C. Assertion (A) is true, but Reason (R) is false.
- D. Assertion (A) is false, but Reason (R) is true.
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Q21
short answer
2 marks
Translate the following statements into balanced chemical equations:
(a) Aluminium reacts with copper chloride to form aluminium chloride and copper.
(b) Zinc reacts with sodium hydroxide to give sodium zincate and hydrogen gas.
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Q22
short answer
2 marks
(a) (i) What is an alloy?
(ii) Write the composition of solder and the property which makes it suitable for welding electric wires.
OR
(b) During electrolytic refining of silver:
(i) What are the electrodes – cathode and anode made up of?
(ii) What is anode mud? Why is it called so?
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Q23
short answer
2 marks
Give reasons:
(a) During a breathing cycle, the lungs always contain a residual volume of air.
(b) As compared to oxygen, carbon dioxide is mostly transported in dissolved form in our blood.
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Q24
short answer
2 marks
(a) Explain how tendrils help a pea plant climb up other plants or fences.
OR
(b) List two major limitations of the use of electrical impulses as a means of communication between cells in multicellular organisms.
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Q25
short answer
2 marks
An object is placed 25 cm in front of a concave mirror of focal length 15 cm. Use mirror formula and new cartesian sign convention to determine the position of the image formed.
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Q26
short answer
2 marks
Draw a ray diagram to show the path of a ray of light which falls obliquely on one of the faces of an equilateral triangular prism made of glass and mark on it the angle of incidence ($\angle i$) and the angle of deviation ($\angle D$).
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Q27
short answer
3 marks
(a) Write the name and chemical formula of a sodium compound which is sometimes added for faster cooking. How is it produced from sodium chloride as one of the raw materials? Give chemical equation for the reaction involved.
(b) The compound mentioned in (a) above is also an ingredient of antacids. Why?
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Q28
short answer
3 marks
Define a displacement reaction. Name a displacement reaction which is highly exothermic and has its use in joining railway tracks. Explain the process with a balanced chemical equation of the reaction that occurs.
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Q29
short answer
3 marks
(a) Write the end products of the breakdown of pyruvate in yeast cells and in our muscle cells under anaerobic conditions.
(b) In which part of the cell does the above process take place?
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Q30
short answer
3 marks
(a) Explain the process of translocation of food and other substances in the phloem of plants.
OR
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Q31
short answer
3 marks
2 $\Omega$, 3 $\Omega$ and 6 $\Omega$ resistors are connected in such a way that the resultant resistance of the combination is (a) 1 $\Omega$, and (b) 4 $\Omega$. Justify your answer in each case.
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Q31
short answer
3 marks
Show the arrangement of three resistors of $2\ \Omega$, $3\ \Omega$ and $6\ \Omega$ which are connected in such a way that the total/equivalent resistance of the combination is (a) $1\ \Omega$, and (b) $4\ \Omega$. Justify your answer in each case.
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Q31
long answer
5 marks
When dry crystals of ferrous sulphate were heated in a dry boiling tube, some tiny water droplets were observed in the tube after some time.
(i) State the source of these water droplets.
(ii) Write the colour change observed during heating.
(iii) Write the balanced chemical equation of the reaction that occurs during heating.
(iv) How many water molecules are attached per formula unit of ferrous sulphate crystal ?
(v) Write the molecular formula of crystalline form of (I) copper sulphate, and (II) sodium carbonate.
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Q32
short answer
3 marks
In the diagram, a small strip AB of aluminium is kept horizontally between the poles of a powerful horse-shoe magnet. This strip is connected to a battery and a key. Study the given arrangement.
(a) State Fleming’s left-hand rule.
(b) Explain Fleming’s left-hand rule:
(i) What happens when the current flows from B to A in the strip?
(ii) What happens when the current flows from A to B in the strip?
(iii) If the strip AB is kept parallel to the magnetic field and then current is passed through it from B to A, what happens? Justify your answer.
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Q32
long answer
3 marks
As shown in the figure a small aluminum rod AB is suspended horizontally between the poles of a strong horseshoe magnet. This rod is also connected with a battery and a key. Study the arrangement shown.
(a) State Fleming’s left-hand rule.
(b) Apply Fleming’s left-hand rule to determine :
(i) What is observed when a current is passed from B to A in the rod ?
(ii) What is observed when a current is passed from A to B in the rod ?
(iii) What is observed when the rod AB is aligned parallel to the magnetic field and current is passed through it from B to A ?
Justify your answer in this case.
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Q33
short answer
3 marks
Define the term biological magnification.
(b) In the given aquatic food chain, which trophic level will have highest effect of biological magnification and why ?
Phytoplankton → Zooplankton → Fishes → Human
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Q33
short answer
State the source of these water droplets.
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Q34
long answer
5 marks
(a) Name and state in brief the process used to obtain sodium hydroxide from brine. In this process, along with the main product (i.e., sodium hydroxide), two gases A and B are also produced at the two electrodes. Name A and B specifying the name of their respective electrodes. One of these gases, when reacting with dry calcium hydroxide, produces a compound C which is used as an oxidising agent in many chemical industries as well as to make drinking water free from germs. Name C and write the chemical equation for the reaction in its formation.
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Q34
short answer
Write the colour change observed during heating.
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Q35
short answer
Write the balanced chemical equation of the reaction that occurs during heating.
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Q35
long answer
5 marks
(a) (i) Define the term power of accommodation of human eye. What happens to the image distance in the eyes when the distance of an object is increased gradually from about 5 m to 500 m from our eyes ? Name and explain the role of the part of human eye responsible for it in this case.
(ii) A person is unable to see distinctly the objects placed beyond 2 m from his eyes. Name the defect of vision the person is suffering from. List two possible causes of this defect and write the type of lenses used for the correction of this defect.
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Q36
short answer
How many water molecules are attached per formula unit of ferrous sulphate crystal?
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Q36
long answer
5 marks
(a) (i) In which form is the information for inheritance of features transmitted from one generation to the next generation ?
(ii) Differentiate between binary fission in Amoeba and Leishmania.
(iii) “Fragmentation cannot be a method of reproduction in all multicellular organisms.” Justify this statement.
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Q37
short answer
Write the molecular formula of crystalline form of (I) copper sulphate, and (II) sodium carbonate.
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Q37
short answer
All compounds of carbon which contain only carbon and hydrogen are called hydrocarbons. Among these, saturated hydrocarbons are called ‘alkanes’, unsaturated compounds with one or more double bonds are called ‘alkenes’ and compounds containing one or more triple bonds are called ‘alkynes’.
(a) Identify the following compound and write its name.
CH$_3$ − C $\equiv$ CH
(b) How do saturated and unsaturated carbon compounds differ in terms of the flame produced by them on burning ?
(c) (i) Which type of hydrocarbons undergo addition reactions ? Show with an example.
OR
(c) (ii) What are structural isomers ? Draw two structural isomers of butane (C$_4$H$_{10}$).
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Q38
short answer
38. The process of determining the sex of a newborn is purely genetic. But still many people in some societies believe that only the woman (mother) is responsible for determination of the sex of the child and blame her. In fact, the sex of the child is genetically determined. But there are some animals where sex is not genetically determined.
(a) Define sex chromosomes.
(b) Mention one example of animals where sex is not genetically determined. How is sex determined in these animals ? Explain.
(c) (i) Does the genetic combination of the mother play a significant role in determining the sex of newborn ? Explain.
OR
(c) (ii) How is equal genetic contribution of male and female parents ensured in progeny ?
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Q39
long answer
5 marks
(i) Name and explain the phenomenon of light responsible to make the path of a beam of light visible when it enters a smoke/dust-filled room through a small hole. Also state the dependence of the colour of the light we receive on the size of the particles of the medium through which the light passes.
(ii) A person suffering from presbyopia needs spectacles having bifocal lenses. If the power of two lenses used in his spectacles is +2.0 D and -0.5 D, which one of the two lenses is for the correction of his distant vision and what is its focal length ?
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Q39
short answer
39. In a domestic circuit, six LED bulbs and a ceiling fan are arranged as per the circuit shown in the figure. The source voltage is 220 volts and the power rating of each device is marked in the circuit diagram. Two fuses F$_1$ and F$_2$ are also provided in the circuit. Based on the circuit diagram, answer the following questions :
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Q45
short answer
1 mark
Mention one example of animals where sex is not genetically determined. How is sex determined in these animals? Explain.
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Q46
short answer
2 marks
(i) Does the genetic combination of the mother play a significant role in determining the sex of newborn? Explain.
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Q47
short answer
2 marks
(ii) How is equal genetic contribution of male and female parents ensured in progeny?
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Q48
short answer
1 mark
State what happens when (i) only key $K_1$ is closed, (ii) and key $K_2$ is also closed.
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Q49
short answer
1 mark
Find the current drawn by the bulb L.
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Q50
short answer
2 marks
Calculate the resistance of the bulb A. Find the total resistance offered by the circuit to the flow of current when only key $K_2$ is closed.
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Q51
short answer
2 marks
What would happen to the glow of the bulbs in the circuit when $K_1$ and $K_2$ both are closed and the fuse $F_1$ melts suddenly? Give reason to justify your answer.
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