Q1
mcq
1 mark
2 g of yellow sulphur powder is burnt in a china dish and the fumes are collected in a test tube. Water is added in the test tube and the solution is tested separately with blue and red litmus paper. The correct option is :
- A. Blue litmus remains blue and red litmus turns blue.
- B. Blue litmus turns red and red litmus remains red.
- C. Blue litmus turns red and red litmus turns blue.
- D. Blue litmus remains blue and red litmus remains red.
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Q2
mcq
1 mark
You want to test for hardness of water but hard water is not available in the laboratory. Which of the following substances can be dissolved in pure water to make it hard?
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Q3
mcq
In the electrolysis of water, if the mass of the gas collected at the anode is $m_a$ and the mass of the gas collected at the cathode is $m_c$, the value of $(m_c/m_a)$ is :
- A. 8
- B. 16
- C. $\frac{1}{16}$
- D. $\frac{1}{8}$
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Q4
mcq
Consider the following substances :
(i) Acidified $K_2Cr_2O_7$
(ii) Alkaline $KMnO_4$
(iii) Oxygen
(iv) Hydrogen
Out of these, the commonly used oxidising agents are :
- A. (i) and (ii) only
- B. (ii) and (iii) only
- C. (i), (ii) and (iii)
- D. (i), (ii) and (iv)
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Q5
mcq
The metal which melts when kept on the palm is :
- A. Sodium
- B. Potassium
- C. Lithium
- D. Gallium
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Q6
mcq
Select from the following compounds which is not a base :
- A. Sodium hydroxide
- B. Calcium hydroxide
- C. Sodium sulphate
- D. Zinc oxide
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Q7
mcq
When an object is placed beyond $2F$ of a convex lens, the nature of the image formed is :
- A. Real, inverted and diminished
- B. Real, erect and magnified
- C. Virtual, erect and magnified
- D. Real, inverted and magnified
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Q8
mcq
When a narrow beam of white light passes through a glass prism it splits into its component colours? This phenomenon is called :
- A. Diffusion of light
- B. Total reflection of light
- C. Scattering of light
- D. Dispersion of light
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Q9
mcq
A material used for making heating elements of electrical heating devices should have :
- A. High resistivity and high melting point.
- B. High resistivity and low melting point.
- C. Low resistivity and high melting point.
- D. Low resistivity and low melting point.
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Q10
mcq
The resistance of a wire does not depend on its :
- A. Length
- B. Area of cross-section
- C. Shape
- D. Material
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Q11
mcq
The shape of magnetic field lines produced (i) inside a solenoid (ii) around a straight conductor, both carrying current of the same magnitude are, respectively :
- A. (i) straight, (ii) circular
- B. (i) circular, (ii) circular
- C. (i) straight, (ii) straight
- D. (i) circular, (ii) straight
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Q12
mcq
Which one of the following properties of Carbon is not responsible for its formation of large number of compounds ?
- A. Tetravalency
- B. Isomerism
- C. Allotropy
- D. Catenation
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Q13
mcq
Which one of the following molecules is produced initially when glucose breaks down in the cytoplasm of a cell in aerobic as well as anaerobic respiration ?
- A. Lactic acid
- B. Ethanol
- C. Carbon dioxide
- D. Pyruvate
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Q14
mcq
As compared to daytime, the amount of carbon dioxide released by the plants during night is more because :
- A. It is not produced during daytime.
- B. It is stored in the leaves of plants during daytime.
- C. Major amount of carbon dioxide produced is used up for photosynthesis during daytime.
- D. Plants do not respire during daytime.
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Q17
mcq
Assertion (A) : $\mathrm{MnO_2 + 4HCl \rightarrow MnCl_2 + 2H_2O + Cl_2}$ is a redox reaction.
Reason (R) : In this reaction, HCl is oxidised to $\mathrm{Cl_2}$ and $\mathrm{MnO_2}$ is reduced to $\mathrm{MnCl_2}$.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the 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) : Cytokinins are present, in greater concentration in areas of rapid cell division such as fruits and seeds.
Reason (R) : Cytokinins promote cell division.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the 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): A rainbow is an artificial spectrum of white light appearing in the sky after a rain shower.
Reason (R): The water droplets act like small prisms.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the 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): Each human trait is influenced by both paternal and maternal DNA.
Reason (R): As compared to the father, the mother contributes more amount of genetic material to the child.
- A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the 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
(a) Find the magnification of the image formed by a spherical mirror from the following data: $u = 20\ \mathrm{cm}$, $f = 15\ \mathrm{cm}$.
OR
(b) Draw a labelled ray diagram for the image formation by a concave mirror when an object is placed between its centre of curvature and focus.
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Q22
short answer
2 marks
When leaves of the soil they develop into new plants, but leaves of a lemon plant cannot do so. Why? Name the method of reproduction by which these plants multiply.
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Q23
short answer
2 marks
(a) State any one advantage of using cloth bags over plastic bags.
(b) List any two methods by which the solid wastes generated in urban areas can be safely disposed off.
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Q24
mcq
2 marks
(a) Two metals A and B react with cold water and hot water respectively, while metal C does not react with water but reacts with steam. Metal D does not react with water at all. Identify the metals A, B, C and D.
OR
(b) When two compounds namely sodium chloride and calcium chloride are heated directly, one by one on the flame of a burner, they impart different colours to the flame.
(i) Name the colour imparted by (1) sodium chloride and (2) calcium chloride.
(ii) Are these compounds soluble in organic solvents such as kerosene or petrol? Justify your answer.
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Q25
short answer
2 marks
Differentiate between direct and alternating current. Name the type of current produced by the power plants in our country. Also state its frequency.
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Q25
short answer
3 marks
(i) Differentiate between a solenoid and a circular coil.
(ii) Explain how a solenoid can be made in a school laboratory.
(iii) Write one use of the strong magnetic field produced inside a current carrying solenoid.
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Q26
short answer
2 marks
Justify this statement with the help of the law of inheritance: a child receives the equal amount of genetic material from both parents.
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Q26
short answer
3 marks
With the help of a labelled circuit diagram, illustrate the pattern of the magnetic field lines of the magnetic field produced around a straight current carrying conductor. Explain how, with the help of right-hand thumb rule, we can determine and mark the direction of magnetic field lines due to a current.
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Q27
short answer
3 marks
White light is dispersed into seven visible coloured components by a glass prism. Name the colour which bends (i) the most and (ii) the least.
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Q27
short answer
3 marks
Observe the given diagram and answer the following questions :
(a) Write a balanced chemical equation for the reaction taking place in the beaker.
(b) Name the two types of reactions in which the above reaction can be placed, giving justification for each.
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Q28
short answer
3 marks
How can the coloured components of white light be recombined after a prism has separated them ? Draw a labelled diagram to justify your answer.
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Q28
short answer
3 marks
Write any two ways by which plants obtain carbon dioxide. What causes the opening and closing of the stomata ?
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Q29
short answer
3 marks
An organic compound X when reacts with sodium liberates hydrogen. The same compound X when heated at 443 K in the presence of concentrated sulphuric acid gives an unsaturated hydrocarbon.
(i) Identify X
(ii) Write the chemical equations for the above mentioned reactions and state the role of concentrated sulphuric acid in the second reaction.
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Q29
short answer
3 marks
Explain how oxygen is delivered to all parts of the body in human beings. In what form is carbon dioxide transported in our blood ?
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Q30
short answer
3 marks
(i) Why are carbon compounds exceptionally stable ?
(ii) Differentiate between saturated a
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Q32
short answer
3 marks
(i) Why are carbon compounds exceptionally stable? (ii) Differentiate between saturated and unsaturated compounds. Give structures of both the types of compounds having three carbon atoms in their molecules.
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Q33
long answer
Construct a food chain of four trophic levels operating in a grassland. If the energy available to the organisms of the $4^{\text{th}}$ trophic level is 75 joules, how much energy was available with the organisms of the $2^{\text{nd}}$ trophic level for transfer to the next trophic level? Justify your answer.
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Q33
short answer
3 marks
Why is the flow of energy unidirectional in a food chain?
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Q35
mcq
5 marks
An aqueous solution turns blue litmus red. Which of the following solutions when added in excess would reverse the change? Out of the following, which compound/compounds will turn the phenolphthalein solution pink? Name a gas whose aqueous solution is basic. Write the formula/name of this solution. A basic substance is used to treat a honey-bee sting. Why? Name the acid which is present in (1) Tomato and (2) Tamarind.
- A. Lemon juice
- B. Magnesium hydroxide
- C. Vinegar
- D. Calcium sulphate
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Q35
short answer
5 marks
Define water of crystallisation. Write the chemical name and formula of a compound having water of crystallisation in its molecule and appears blue. Write the chemical formula of bleaching powder. Write a balanced chemical equation of the reaction involved in its preparation. List its three uses.
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Q39
mcq
An aqueous solution turns blue litmus red. Which of the following solutions when added in excess would reverse the change?
- A. Lemon juice
- B. Magnesium hydroxide
- C. Vinegar
- D. Calcium sulphate
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Q40
mcq
Out of the following, which compound/compounds will turn the phenolphthalein solution pink?
- A. $\mathrm{CH_3COOH}$
- B. $\mathrm{Ca(OH)_2}$
- C. $\mathrm{HCl}$
- D. $\mathrm{NaOH}$
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Q41
short answer
Name a gas whose aqueous solution is basic. Write the formula/name of this solution.
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Q42
short answer
A basic substance is used to treat a honey-bee sting. Why?
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Q43
short answer
5 marks
Name the acid which is present in (1) Tomato and (2) Tamarind.
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Q45
short answer
Write the chemical name and formula of a compound having water of crystallisation in its molecule and appears blue.
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Q46
short answer
5 marks
Write the chemical formula of bleaching powder. Write a balanced chemical equation of the reaction involved in its preparation. List its three uses.
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Q47
short answer
Calculate the resistance of an aluminium wire of length 1 m and area of cross-section $2\,\mathrm{mm^2}$. Resistivity of aluminium is $2.63\times10^{-8}\,\Omega\,\mathrm{m}$.
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Q48
short answer
5 marks
From the values given below, plot a graph of $I$ versus $V$. Show that
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The iron pillar in Qutab Minar complex in Delhi was built 1600 years ago. It is still standing intact and shows no signs of rusting even today. This shows that the ancient metallurgists of India in those times had fully developed metallurgical processes as well as the techniques of protection of different metals. The protection of metals, was done by several processes like coating of a thin film of another metal, alloying etc.
Q49
short answer
1 mark
Where is iron placed in the reactivity series of metals? Write the form/forms in which its ores are found in nature.
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Q50
short answer
1 mark
Differentiate between roasting and calcination.
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Q51
short answer
2 marks
Explain any two methods that are employed to prevent rusting/corrosion of metals.
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Q52
short answer
2 marks
Why is aluminium used to join railway tracks or the cracked machine parts of iron? Write a balanced chemical equation for the reaction which occurs.
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Q53
short answer
1 mark
How is the brain protected from shocks and injuries ?
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Q54
short answer
1 mark
Write the main functions of (i) sensory neuron and (ii) motor neuron in a reflex arc.
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Q55
short answer
2 marks
Which part of the brain is involved in activities like (i) picking a pencil and (ii) vomiting ? State whether these actions are voluntary or involuntary.
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Q56
short answer
2 marks
How does the central nervous system communicate with the other parts of the body to carry out various activities ? Name two components of this system.
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